Refactor panes and filesystem; replace FUSE with 9P

Consolidate pane, layout, memory and host code. Serve 9P by default over Unix sockets, with runtime mounts and optional TCP/QUIC transports. Remove FUSE and obsolete proof-of-concept examples.

Fix highlighting and terminal-history performance, expand differential and stress-test infrastructure, sort navigation results while preserving the next occurrence, add syntax-colored Braille minimaps, remove SPC-k, and document 9P interaction as a repository skill.

1 files changed, 1867 insertions, 0 deletions

diff --git a/test/pdf.zig b/test/pdf.zig
new file mode 100644
index 00000000..b2d03bb8
--- /dev/null
+++ b/test/pdf.zig
@@ -0,0 +1,1867 @@
+const std = @import("std");
+const pardes = @import("pardes");
+const panes = pardes.panes;
+const look = pardes.look;
+const pdf_impl = panes.Pdf.pdf;
+const image = pardes.image;
+const config = pardes.config;
+const builtins = pardes.builtins;
+const layout = pardes.layout;
+const dump = pardes.dump;
+
+const Pardes = pardes.Pardes;
+const Builtin = builtins.registry.Builtin();
+const Key = pardes.Key;
+const Event = pardes.Event;
+const Mode = pardes.Pane.Mode;
+const Surface = pardes.Surface;
+const ImagePlace = pardes.ImagePlace;
+const PdfFitMode = panes.Pdf.FitMode;
+const PdfTintMode = panes.Pdf.TintMode;
+const pdf_enabled = panes.Pdf.enabled;
+const platform = pardes.platform;
+const themes = pardes.themes;
+const pdf_raster_policy = pardes.pdf_raster_policy;
+const PDF_PAGE_GAP_PX = pardes.PDF_PAGE_GAP_PX;
+const BOX_H = pardes.BOX_H;
+const sel_slot = @intFromEnum(config.select_button);
+const pane_tail = " " ++ config.pane_builtins_str;
+
+fn hasPdf(pane: *const pardes.Pane) bool {
+    return if (comptime pdf_enabled) pane.pdf != null else false;
+}
+
+test "PDF mounted bytes own their source after the caller frees it" {
+    if (!pdf_enabled or platform == .web) return;
+    const gpa = std.testing.allocator;
+    const source = try pardes.filesystem.readFile(gpa, "docs/design.pdf");
+    var document = pdf_impl.Document.openBytes(source) catch |err| {
+        gpa.free(source);
+        return err;
+    };
+    @memset(source, 0);
+    gpa.free(source);
+    defer document.deinit();
+
+    var original = try pdf_impl.Document.open("docs/design.pdf");
+    defer original.deinit();
+    try std.testing.expectEqual(original.pages, document.pages);
+    try std.testing.expectEqual(try original.pageSize(0), try document.pageSize(0));
+    const raster = try document.render(gpa, 0);
+    defer gpa.free(raster.rgba);
+    try std.testing.expect(raster.rgba.len > 0);
+}
+
+test "explicit OS PDF opens and reloads keep their namespace path" {
+    if (!pdf_enabled or platform == .web) return;
+    const gpa = std.testing.allocator;
+    var tmp = std.testing.tmpDir(.{});
+    defer tmp.cleanup();
+    const original = try pdf_impl.makeOutlineTestPdf(gpa);
+    defer gpa.free(original);
+    const replacement = try pdf_impl.makeNoOutlineTestPdf(gpa);
+    defer gpa.free(replacement);
+    try tmp.dir.writeFile(std.testing.io, .{ .sub_path = "live.pdf", .data = original });
+    var directory_buffer: [4096]u8 = undefined;
+    const directory_len = try tmp.dir.realPath(std.testing.io, &directory_buffer);
+    const path = try std.fmt.allocPrint(gpa, "/n/os{s}/live.pdf", .{directory_buffer[0..directory_len]});
+    defer gpa.free(path);
+    const p = try Pardes.init(gpa, .{ .file = path, .cols = 80, .rows = 24 });
+    defer p.deinit();
+    const pane = p.panes[0].?;
+    try std.testing.expectEqualStrings(path, pane.pdf.?.path);
+    try std.testing.expectEqual(@as(usize, 3), pane.pdf.?.page_count);
+    var watched = false;
+    while (p.nextEffect()) |effect| {
+        if (effect == .watch and effect.watch.pane == 0 and effect.watch.on) watched = true;
+    }
+    try std.testing.expect(watched);
+    try tmp.dir.writeFile(std.testing.io, .{ .sub_path = "live.pdf", .data = replacement });
+    try std.testing.expect(p.reloadWatchedFile(0, &.{}));
+    try std.testing.expectEqualStrings(path, pane.pdf.?.path);
+    try std.testing.expectEqual(@as(usize, 1), pane.pdf.?.page_count);
+}
+
+test "PDF feature gates keep argv and builtin behavior coherent" {
+    const maybe_fit = std.meta.stringToEnum(Builtin, "PdfFit");
+    const maybe_tint = std.meta.stringToEnum(Builtin, "PdfTint");
+    const maybe_sections = std.meta.stringToEnum(Builtin, "PdfSections");
+    try std.testing.expectEqual(pdf_enabled, maybe_fit != null);
+    try std.testing.expectEqual(pdf_enabled, maybe_tint != null);
+    try std.testing.expectEqual(pdf_enabled, maybe_sections != null);
+    if (pdf_enabled) {
+        try std.testing.expectEqualStrings("tz", config.leader_path.get(maybe_fit.?).?);
+        try std.testing.expectEqualStrings("ti", config.leader_path.get(maybe_tint.?).?);
+        try std.testing.expectEqualStrings("ts", config.leader_path.get(maybe_sections.?).?);
+    } else if (platform != .web) {
+        const p = try Pardes.init(std.testing.allocator, .{
+            .file = "docs/design.pdf",
+            .cols = 80,
+            .rows = 24,
+        });
+        defer p.deinit();
+        const pane = p.panes[0].?;
+        try std.testing.expect(pane.file != null);
+        try std.testing.expect(pane.image == null);
+        try std.testing.expect(!hasPdf(pane));
+    }
+}
+
+test "PDF dump fallback remains a byte-preserving file" {
+    const gpa = std.testing.allocator;
+    const path = "/definitely/missing/pardes-dump-fallback.PDF";
+    const source = "%PDF embedded fallback bytes\x00\xff";
+    const encoded = try dump.encodeBytes(gpa, source);
+    defer gpa.free(encoded);
+    const ids = [_]usize{0};
+    const columns = [_]dump.Column{.{ .panes = &ids }};
+    const saved_panes = [_]dump.Pane{.{
+        .kind = .image,
+        .tag = "pdf 3/9 height PdfFit full PdfTint PdfSections " ++ path ++ " Keep Del",
+        .body = "",
+        .scroll = 2,
+        .cols = 80,
+        .rows = 24,
+        .image = .{ .path = path, .bytes_b64 = encoded },
+    }};
+    const state = dump.State{
+        .screen = .{ .cols = 80, .rows = 24 },
+        .columns = &columns,
+        .panes = &saved_panes,
+    };
+    var out: std.Io.Writer.Allocating = .init(gpa);
+    defer out.deinit();
+    try std.zon.stringify.serialize(state, .{ .whitespace = true }, &out.writer);
+
+    const restored = try Pardes.initFromDump(gpa, .{ .tty_only = true }, out.written());
+    defer restored.deinit();
+    const pane = restored.panes[0].?;
+    try std.testing.expect(pane.file != null);
+    try std.testing.expect(pane.image == null);
+    try std.testing.expect(!hasPdf(pane));
+    try std.testing.expectEqualStrings(path, pane.file.?.path);
+    try std.testing.expectEqualSlices(u8, source, pane.file.?.content);
+    try std.testing.expect(pane.tag_init);
+    try std.testing.expectEqualStrings(" Keep Del", pane.tag_tail[0..pane.tag_tail_len]);
+}
+
+test "PdfSections Look follows the exact owning PDF, not an equal path" {
+    if (!pdf_enabled or platform == .web) return;
+    const gpa = std.testing.allocator;
+    var tmp = std.testing.tmpDir(.{});
+    defer tmp.cleanup();
+    const fixture = try pdf_impl.makeOutlineTestPdf(gpa);
+    defer gpa.free(fixture);
+    try tmp.dir.writeFile(std.testing.io, .{ .sub_path = "outline.pdf", .data = fixture });
+    var path_buf: [256]u8 = undefined;
+    const path = try std.fmt.bufPrint(&path_buf, ".zig-cache/tmp/{s}/outline.pdf", .{tmp.sub_path});
+
+    const p = try Pardes.init(gpa, .{ .file = path, .cols = 80, .rows = 28 });
+    defer p.deinit();
+    const first = p.panes[0].?;
+    // Bare normal-mode `f` on a PDF dispatches the PdfSections builtin.
+    p.update(.{ .key = .{ .cp = 'f', .text = "f" } });
+    const first_output_id = first.search_pane orelse return error.MissingPdfSectionsOutput;
+    const first_output = p.panes[first_output_id].?;
+    try std.testing.expect(panes.Pdf.isSectionsOutput(first_output));
+    try std.testing.expect(first_output.file.?.content.len > 0);
+
+    // A clean result is re-armed in place without rebuilding it.
+    const first_revision = first_output.file.?.revision;
+    panes.Pdf.openSections(p, 0);
+    try std.testing.expectEqual(first_output_id, first.search_pane.?);
+    try std.testing.expectEqual(first_revision, first_output.file.?.revision);
+
+    const duplicate_id = p.freeSlot() orelse return error.NoDuplicatePdfSlot;
+    const duplicate = try panes.Pdf.openPane(p, duplicate_id, path, 0);
+    p.placeDoc(0, duplicate_id, duplicate);
+    layout.compute(p);
+    panes.Pdf.openSections(p, duplicate_id);
+    const duplicate_output_id = duplicate.search_pane orelse return error.MissingDuplicatePdfSections;
+
+    const first_row = std.mem.sliceTo(first_output.file.?.content, '\n');
+    const target = first_row[0 .. std.mem.indexOfScalar(u8, first_row, ' ') orelse first_row.len];
+    p.lookAt(first_output_id, target);
+    try std.testing.expectEqual(@as(usize, 0), p.active);
+    p.lookAt(duplicate_output_id, target);
+    try std.testing.expectEqual(duplicate_id, p.active);
+
+    // Once the original document is gone, its output cannot reinterpret an
+    // old ordinal against the still-open equal-path duplicate.
+    try std.testing.expect(pardes.test_api.runBuiltin(p, "Del", 0, "", null));
+    p.active = first_output_id;
+    p.lookAt(first_output_id, target);
+    try std.testing.expectEqual(first_output_id, p.active);
+}
+
+test "PdfSections caches an empty outline output" {
+    if (!pdf_enabled or platform == .web) return;
+    const gpa = std.testing.allocator;
+    var tmp = std.testing.tmpDir(.{});
+    defer tmp.cleanup();
+    const fixture = try pdf_impl.makeNoOutlineTestPdf(gpa);
+    defer gpa.free(fixture);
+    try tmp.dir.writeFile(std.testing.io, .{ .sub_path = "plain.pdf", .data = fixture });
+    var path_buf: [256]u8 = undefined;
+    const path = try std.fmt.bufPrint(&path_buf, ".zig-cache/tmp/{s}/plain.pdf", .{tmp.sub_path});
+    const p = try Pardes.init(gpa, .{ .file = path });
+    defer p.deinit();
+    panes.Pdf.openSections(p, 0);
+    const pane = p.panes[0].?;
+    const output_id = pane.search_pane orelse return error.MissingEmptyPdfSections;
+    try std.testing.expectEqual(@as(usize, 0), p.panes[output_id].?.file.?.content.len);
+    const serial = p.panes[output_id].?.serial;
+    panes.Pdf.openSections(p, 0);
+    try std.testing.expectEqual(output_id, pane.search_pane.?);
+    try std.testing.expectEqual(serial, p.panes[output_id].?.serial);
+}
+
+test "SDL PDF raster policy is materially denser than Kitty" {
+    try std.testing.expect(
+        pardes.sdl_pdf_raster_policy.dpi >= pardes.kitty_pdf_raster_policy.dpi * 2,
+    );
+    try std.testing.expect(
+        pardes.sdl_pdf_raster_policy.max_dimension >
+            pardes.kitty_pdf_raster_policy.max_dimension * 3,
+    );
+    try std.testing.expect(!pardes.kitty_pdf_raster_policy.match_viewport);
+    try std.testing.expect(pardes.sdl_pdf_raster_policy.match_viewport);
+}
+
+test "watched PDF reload replaces MuPDF state and preserves the reading view" {
+    if (!pdf_enabled or platform == .web) return;
+
+    const gpa = std.testing.allocator;
+    var tmp = std.testing.tmpDir(.{});
+    defer tmp.cleanup();
+    const original = try pdf_impl.makeOutlineTestPdf(gpa);
+    defer gpa.free(original);
+    const replacement = try pdf_impl.makeNoOutlineTestPdf(gpa);
+    defer gpa.free(replacement);
+    try tmp.dir.writeFile(std.testing.io, .{ .sub_path = "live.pdf", .data = original });
+    var path_buf: [256]u8 = undefined;
+    const path = try std.fmt.bufPrint(
+        &path_buf,
+        ".zig-cache/tmp/{s}/live.pdf",
+        .{tmp.sub_path},
+    );
+
+    const p = try Pardes.init(gpa, .{ .file = path, .cols = 80, .rows = 28 });
+    defer p.deinit();
+    var watched = false;
+    while (p.nextEffect()) |effect| switch (effect) {
+        .watch => |watch| if (watch.pane == 0 and watch.on) {
+            watched = true;
+        },
+        else => {},
+    };
+    try std.testing.expect(watched);
+
+    const pane = p.panes[0].?;
+    const state = &pane.pdf.?;
+    try std.testing.expectEqual(@as(usize, 3), state.page_count);
+    panes.Pdf.openSections(p, 0);
+    const sections_id = pane.search_pane orelse return error.MissingPdfSectionsOutput;
+    const sections = p.panes[sections_id].?;
+    try std.testing.expect(sections.file.?.content.len > 0);
+
+    p.native_images = true;
+    state.fit = .height;
+    state.tint = .full;
+    state.pan_x = 1234;
+    state.pan_y = 4321;
+    try state.setSearchQuery(p.pdf_gpa, "needle");
+    panes.Pdf.setPage(p, pane, 2);
+    var frame = std.heap.ArenaAllocator.init(gpa);
+    defer frame.deinit();
+    _ = try p.render(frame.allocator());
+    state.text_scroll = 7;
+    state.search_hit = 4;
+    state.search_reveal_pending = false;
+    const reveal_viewport_w = state.reveal_viewport_w;
+    const reveal_viewport_h = state.reveal_viewport_h;
+    const reveal_fit = state.reveal_fit;
+    const reveal_viewport_valid = state.reveal_viewport_valid;
+    const old_revision = panes.Pdf.rasterForPage(state, 2).?.revision;
+    const old_revision_counter = state.next_raster_revision;
+    const anchor_fraction: f64 = 0.375;
+    state.document_scroll_y = @as(f64, @floatFromInt(state.page_starts[2])) +
+        anchor_fraction * @as(f64, @floatFromInt(state.page_heights[2]));
+    state.scroll_to_page_pending = false;
+    state.layout_anchor_pending = false;
+    pane.cur_row = 9;
+    pane.cur_col = 8;
+
+    try tmp.dir.writeFile(std.testing.io, .{ .sub_path = "live.pdf", .data = replacement });
+    try std.testing.expect(p.reloadWatchedFile(0, &.{}));
+
+    try std.testing.expectEqual(@as(usize, 1), state.page_count);
+    try std.testing.expectEqual(@as(usize, 0), state.page);
+    try std.testing.expectEqual(PdfFitMode.height, state.fit);
+    try std.testing.expectEqual(PdfTintMode.full, state.tint);
+    try std.testing.expectEqual(@as(u16, 1234), state.pan_x);
+    try std.testing.expectEqual(@as(u16, 4321), state.pan_y);
+    try std.testing.expectEqual(@as(usize, 7), state.text_scroll);
+    try std.testing.expect(state.text_scroll_clamp_pending);
+    try std.testing.expectEqualStrings("needle", state.search_query);
+    try std.testing.expectEqual(@as(usize, 4), state.search_hit);
+    try std.testing.expectEqual(reveal_viewport_w, state.reveal_viewport_w);
+    try std.testing.expectEqual(reveal_viewport_h, state.reveal_viewport_h);
+    try std.testing.expectEqual(reveal_fit, state.reveal_fit);
+    try std.testing.expectEqual(reveal_viewport_valid, state.reveal_viewport_valid);
+    try std.testing.expectEqual(old_revision_counter, state.next_raster_revision);
+    try std.testing.expectEqual(@as(usize, 0), state.rasters_len);
+    try std.testing.expect(state.layout_anchor_pending);
+    try std.testing.expectEqual(@as(usize, 2), state.layout_anchor_page);
+    try std.testing.expectApproxEqAbs(anchor_fraction, state.layout_anchor_fraction, 0.0001);
+    try std.testing.expectEqual(@as(i32, 0), pane.cur_row);
+    try std.testing.expectEqual(@as(i32, 0), pane.cur_col);
+    _ = state.ensureText(p.pdf_gpa);
+    const text_lines = std.mem.count(u8, state.text, "\n") + 1;
+    try std.testing.expect(state.text_scroll < text_lines);
+    try std.testing.expect(!state.text_scroll_clamp_pending);
+
+    // A clean generated outline is derived data: it refreshes in place and
+    // remains the remembered output. This replacement deliberately has none.
+    try std.testing.expectEqual(@as(usize, 0), sections.file.?.content.len);
+    try std.testing.expectEqual(sections_id, state.sections_output.?.pane);
+    try std.testing.expectEqual(sections.file.?.revision, state.sections_output.?.revision);
+
+    _ = frame.reset(.retain_capacity);
+    _ = try p.render(frame.allocator());
+    const fresh_raster = panes.Pdf.rasterForPage(state, 0).?;
+    try std.testing.expect(fresh_raster.revision != old_revision);
+    try std.testing.expect(fresh_raster.revision > old_revision_counter);
+    const expected_scroll = anchor_fraction *
+        @as(f64, @floatFromInt(state.page_heights[0]));
+    const viewport = panes.Pdf.paneViewport(p, pane).?;
+    const max_scroll = @as(f64, @floatFromInt(state.document_height -| viewport.pixel_h));
+    try std.testing.expectApproxEqAbs(@min(expected_scroll, max_scroll), state.document_scroll_y, 0.001);
+
+    // Reopen is transactional: malformed replacement bytes leave the last
+    // good MuPDF handle and every durable setting untouched.
+    const good_handle = state.document.handle;
+    try tmp.dir.writeFile(std.testing.io, .{ .sub_path = "live.pdf", .data = "not a PDF" });
+    try std.testing.expect(!p.reloadWatchedFile(0, &.{}));
+    try std.testing.expectEqual(good_handle, state.document.handle);
+    try std.testing.expectEqual(@as(usize, 1), state.page_count);
+    try std.testing.expectEqualStrings("needle", state.search_query);
+    try std.testing.expect(std.mem.indexOf(u8, pane.msg[0..pane.msg_len], "PDF reload") != null);
+
+    // A user edit breaks the generated-revision token. A later valid reload
+    // updates the document but leaves those user-owned output bytes alone.
+    panes.File.setContent(p, &sections.file.?, try gpa.dupe(u8, "edited sections\n"));
+    try tmp.dir.writeFile(std.testing.io, .{ .sub_path = "live.pdf", .data = original });
+    try std.testing.expect(p.reloadWatchedFile(0, &.{}));
+    try std.testing.expectEqual(@as(usize, 3), state.page_count);
+    try std.testing.expectEqualStrings("edited sections\n", sections.file.?.content);
+
+    // The watch follows the PDF payload's lifetime just like a text file's;
+    // emit the stop while the slot still identifies the disappearing pane.
+    try p.deinitPane(pane);
+    p.panes[0] = null;
+    var unwatched = false;
+    while (p.nextEffect()) |effect| switch (effect) {
+        .watch => |watch| if (watch.pane == 0 and !watch.on) {
+            unwatched = true;
+        },
+        else => {},
+    };
+    try std.testing.expect(unwatched);
+}
+
+test "PDF reload does not re-center an already revealed matching search" {
+    if (!pdf_enabled or platform == .web) return;
+    const gpa = std.testing.allocator;
+    const fixture = try pardes.filesystem.readFile(gpa, "docs/design.pdf");
+    defer gpa.free(fixture);
+    var tmp = std.testing.tmpDir(.{});
+    defer tmp.cleanup();
+    try tmp.dir.writeFile(std.testing.io, .{ .sub_path = "search.pdf", .data = fixture });
+    var path_buf: [256]u8 = undefined;
+    const path = try std.fmt.bufPrint(&path_buf, ".zig-cache/tmp/{s}/search.pdf", .{tmp.sub_path});
+    const p = try Pardes.init(gpa, .{ .file = path, .cols = 80, .rows = 28 });
+    defer p.deinit();
+    p.native_images = true;
+    const pane = p.panes[0].?;
+    const state = &pane.pdf.?;
+    try state.setSearchQuery(p.pdf_gpa, "Pardes");
+    var frame = std.heap.ArenaAllocator.init(gpa);
+    defer frame.deinit();
+    _ = try p.render(frame.allocator());
+    try std.testing.expect(state.search_results != null);
+    try std.testing.expect(state.search_results.?.hit_count > 0);
+    try std.testing.expect(state.reveal_viewport_valid);
+
+    // Reading moved on after the original reveal. A reload retains the query
+    // and rebuilds its quads, but it must not mistake that for a new request to
+    // jump back to the hit.
+    const anchor_page = state.page;
+    const anchor_fraction: f64 = 0.82;
+    state.document_scroll_y = @as(f64, @floatFromInt(state.page_starts[anchor_page])) +
+        anchor_fraction * @as(f64, @floatFromInt(state.page_heights[anchor_page]));
+    state.scroll_to_page_pending = false;
+    state.layout_anchor_pending = false;
+    state.search_reveal_pending = false;
+    const reveal_w = state.reveal_viewport_w;
+    const reveal_h = state.reveal_viewport_h;
+    const reveal_fit = state.reveal_fit;
+
+    // Same semantic document on a fresh generation keeps the expected anchor
+    // easy to state while still rebuilding every MuPDF-owned search object.
+    try tmp.dir.writeFile(std.testing.io, .{ .sub_path = "search.pdf", .data = fixture });
+    try std.testing.expect(p.reloadWatchedFile(0, &.{}));
+    try std.testing.expectEqual(reveal_w, state.reveal_viewport_w);
+    try std.testing.expectEqual(reveal_h, state.reveal_viewport_h);
+    try std.testing.expectEqual(reveal_fit, state.reveal_fit);
+    try std.testing.expect(!state.search_reveal_pending);
+    _ = frame.reset(.retain_capacity);
+    _ = try p.render(frame.allocator());
+
+    const page = @min(anchor_page, state.page_count - 1);
+    const anchored = @as(f64, @floatFromInt(state.page_starts[page])) +
+        anchor_fraction * @as(f64, @floatFromInt(state.page_heights[page]));
+    const viewport = panes.Pdf.paneViewport(p, pane).?;
+    const max_scroll = @as(f64, @floatFromInt(state.document_height -| viewport.pixel_h));
+    try std.testing.expectApproxEqAbs(@min(anchored, max_scroll), state.document_scroll_y, 0.001);
+}
+
+test "MuPDF pane renders, navigates, searches, and round-trips its page" {
+    if (!pdf_enabled or platform == .web) return;
+
+    const gpa = std.testing.allocator;
+    const p = try Pardes.init(gpa, .{
+        .file = "docs/design.pdf",
+        .cols = 80,
+        .rows = 24,
+    });
+    defer p.deinit();
+    const pane = p.panes[0].?;
+    try std.testing.expect(hasPdf(pane));
+    try std.testing.expect(pane.pdf.?.page_count > 1);
+    try std.testing.expectEqual(PdfFitMode.width, pane.pdf.?.fit);
+    try std.testing.expectEqual(@as(u16, 0), pane.pdf.?.pan_x);
+    try std.testing.expectEqual(@as(u16, 0), pane.pdf.?.pan_y);
+    try std.testing.expectEqual(@as(u16, 8), p.cell_pixels.w);
+    try std.testing.expectEqual(@as(u16, 16), p.cell_pixels.h);
+    const initial_tag = try pardes.test_api.tagText(p, p.scratch.allocator(), pane);
+    try std.testing.expect(std.mem.indexOf(u8, initial_tag, "pdf 1/") != null);
+    try std.testing.expect(std.mem.indexOf(u8, initial_tag, " width ") != null);
+    try std.testing.expect(std.mem.indexOf(u8, initial_tag, " height ") == null);
+    try std.testing.expect(std.mem.indexOf(u8, initial_tag, "PdfFit") != null);
+    try std.testing.expect(std.mem.endsWith(u8, initial_tag, pane_tail));
+
+    p.native_images = true;
+    var frame = std.heap.ArenaAllocator.init(gpa);
+    defer frame.deinit();
+    const first = try p.render(frame.allocator());
+    try std.testing.expectEqual(@as(usize, 1), first.nimages);
+    const first_place = first.images[0].?;
+    try std.testing.expect(first_place.rgba.len == first_place.iw * first_place.ih * 4);
+    try std.testing.expectEqual(image.NativeFit.width, first_place.native.fit);
+    const request = panes.Pdf.renderRequest(
+        panes.Pdf.paneViewport(p, pane) orelse return error.MissingPdfViewport,
+        pdf_raster_policy,
+    );
+    try std.testing.expectEqual(pdf_raster_policy.dpi, request.dpi);
+    try std.testing.expectEqual(pdf_raster_policy.max_dimension, request.max_dimension);
+    try std.testing.expectEqual(
+        request,
+        panes.Pdf.rasterForPage(&pane.pdf.?, pane.pdf.?.page).?.request,
+    );
+    try std.testing.expect(@max(first_place.iw, first_place.ih) <= request.max_dimension);
+    if (pdf_raster_policy.match_viewport) {
+        const viewport = panes.Pdf.paneViewport(p, pane) orelse return error.MissingPdfViewport;
+        try std.testing.expectEqual(viewport.pixel_w, request.minimum_width);
+        try std.testing.expectEqual(viewport.pixel_h, request.minimum_height);
+        try std.testing.expect(first_place.iw >= viewport.pixel_w or
+            @max(first_place.iw, first_place.ih) == request.max_dimension);
+        try std.testing.expect(first_place.ih >= viewport.pixel_h or
+            @max(first_place.iw, first_place.ih) == request.max_dimension);
+    } else {
+        try std.testing.expectEqual(@as(u32, 0), request.minimum_width);
+        try std.testing.expectEqual(@as(u32, 0), request.minimum_height);
+    }
+
+    // SDL's raw dy path retains fractions in the placement itself; it does
+    // not leave native pixels fixed while only the underlying cells slide.
+    p.update(.{ .pdf_scroll = .{ .pane = 0, .delta_pixels = 0.25 } });
+    try std.testing.expectEqual(@as(f64, 0.25), pane.pdf.?.document_scroll_y);
+    _ = frame.reset(.retain_capacity);
+    const fractional = try p.render(frame.allocator());
+    try std.testing.expectEqual(first_place.native.revision, fractional.images[0].?.native.revision);
+    try std.testing.expectEqual(@as(f32, -0.25), fractional.images[0].?.native.pixel_offset_y);
+    pane.pdf.?.document_scroll_y = 0;
+
+    // The default reading view moves one exact display-cell distance without
+    // replacing page pixels. Document placement, not texture identity, moves.
+    p.update(.{ .key = .{ .cp = 'j' } });
+    try std.testing.expectEqual(@as(usize, 0), pane.pdf.?.page);
+    try std.testing.expectEqual(@as(f64, p.cell_pixels.h), pane.pdf.?.document_scroll_y);
+    try std.testing.expectEqual(
+        first_place.native.revision,
+        panes.Pdf.rasterForPage(&pane.pdf.?, pane.pdf.?.page).?.revision,
+    );
+    _ = frame.reset(.retain_capacity);
+    const panned = try p.render(frame.allocator());
+    try std.testing.expectEqual(first_place.native.revision, panned.images[0].?.native.revision);
+    try std.testing.expect(panned.images[0].?.native.geometry.?.src.y > first_place.native.geometry.?.src.y);
+
+    const row_scroll = pane.pdf.?.document_scroll_y;
+    pane.pdf.?.document_scroll_y = 0;
+    p.update(.{ .key = .{ .cp = '3' } });
+    p.update(.{ .key = .{ .cp = 'j' } });
+    try std.testing.expectEqual(@as(f64, p.cell_pixels.h * 3), pane.pdf.?.document_scroll_y);
+
+    // Counts survive a shared multi-key prefix. An invalid continuation is
+    // consumed and clears both prefix and count before the following action.
+    pane.pdf.?.document_scroll_y = 0;
+    p.update(.{ .key = .{ .cp = '2' } });
+    p.update(.{ .key = .{ .cp = 'g' } });
+    p.update(.{ .key = .{ .cp = 'j' } });
+    try std.testing.expectEqual(@as(f64, p.cell_pixels.h * 2), pane.pdf.?.document_scroll_y);
+    pane.pdf.?.document_scroll_y = 0;
+    p.update(.{ .key = .{ .cp = '4' } });
+    p.update(.{ .key = .{ .cp = 'g' } });
+    p.update(.{ .key = .{ .cp = '?' } });
+    try std.testing.expectEqual(.none, pane.normal.prefix);
+    try std.testing.expectEqual(@as(u32, 0), pane.normal.count);
+    p.update(.{ .key = .{ .cp = 'j' } });
+    try std.testing.expectEqual(row_scroll, pane.pdf.?.document_scroll_y);
+
+    pane.pdf.?.document_scroll_y = 0;
+    p.update(.{ .key = .{ .cp = 'd', .ctrl = true } });
+    const half_scroll = pane.pdf.?.document_scroll_y;
+    try std.testing.expect(half_scroll > row_scroll);
+    pane.pdf.?.document_scroll_y = 0;
+    p.update(.{ .key = .{ .cp = '2' } });
+    p.update(.{ .key = .{ .cp = 'd', .ctrl = true } });
+    const counted_half = pane.pdf.?.document_scroll_y;
+    try std.testing.expectEqual(half_scroll * 2, counted_half);
+    p.update(.{ .key = .{ .cp = '2' } });
+    p.update(.{ .key = .{ .cp = 'u', .ctrl = true } });
+    try std.testing.expectEqual(@as(f64, 0), pane.pdf.?.document_scroll_y);
+    pane.pdf.?.document_scroll_y = @as(f64, p.cell_pixels.h) * 4;
+    p.update(.{ .key = .{ .cp = '3' } });
+    p.update(.{ .key = .{ .cp = 'k' } });
+    try std.testing.expectEqual(row_scroll, pane.pdf.?.document_scroll_y);
+    pane.pdf.?.document_scroll_y = 0;
+    p.update(.{ .key = .{ .cp = 'f', .ctrl = true } });
+    try std.testing.expect(pane.pdf.?.document_scroll_y >= half_scroll);
+    pane.pdf.?.document_scroll_y = 0;
+    p.update(.{ .key = .{ .cp = '2' } });
+    p.update(.{ .key = .{ .cp = 'f', .ctrl = true } });
+    const key_viewport = panes.Pdf.paneViewport(p, pane).?;
+    const max_key_scroll = @as(f64, @floatFromInt(pane.pdf.?.document_height -| key_viewport.pixel_h));
+    const counted_full = @min(@as(f64, @floatFromInt(key_viewport.pixel_h * 2)), max_key_scroll);
+    try std.testing.expectEqual(counted_full, pane.pdf.?.document_scroll_y);
+    p.update(.{ .key = .{ .cp = '2' } });
+    p.update(.{ .key = .{ .cp = 'b', .ctrl = true } });
+    try std.testing.expectEqual(@max(@as(f64, 0), counted_full - @as(f64, @floatFromInt(key_viewport.pixel_h * 2))), pane.pdf.?.document_scroll_y);
+    try std.testing.expectEqual(
+        first_place.native.revision,
+        panes.Pdf.rasterForPage(&pane.pdf.?, pane.pdf.?.page).?.revision,
+    );
+
+    // At a page boundary both page rasters coexist, the gap remains uncovered,
+    // and a row step crosses it without snapping either page to an edge.
+    //
+    // This lands by ASSIGNMENT, which is a jump and not a fling — and the
+    // travel counter has to say so: the keys above scrolled two screenfuls
+    // without any frame in between to spend that distance, which no shell does
+    // (every wheel batch is followed by a draw). Left unspent it would make the
+    // frame below the first frame of a fling and hand it bands.
+    const viewport = panes.Pdf.paneViewport(p, pane).?;
+    pane.pdf.?.scroll_travel = 0;
+    pane.pdf.?.document_scroll_y = @floatFromInt(
+        pane.pdf.?.page_starts[1] -| viewport.pixel_h / 2,
+    );
+    _ = frame.reset(.retain_capacity);
+    const boundary = try p.render(frame.allocator());
+    try std.testing.expectEqual(@as(usize, 2), boundary.nimages);
+    try std.testing.expectEqual(@as(u32, 0), boundary.images[0].?.native.page);
+    try std.testing.expectEqual(@as(u32, 1), boundary.images[1].?.native.page);
+    const first_bottom = @as(f32, @floatFromInt(
+        boundary.images[0].?.native.geometry.?.dst.y +
+            boundary.images[0].?.native.geometry.?.dst.h,
+    )) + boundary.images[0].?.native.pixel_offset_y;
+    const second_top = @as(f32, @floatFromInt(
+        boundary.images[1].?.native.geometry.?.dst.y,
+    )) + boundary.images[1].?.native.pixel_offset_y;
+    const visible_gap = second_top - first_bottom;
+    try std.testing.expect(visible_gap >= @as(f32, PDF_PAGE_GAP_PX));
+    try std.testing.expect(visible_gap <= @as(f32, PDF_PAGE_GAP_PX + 1));
+    const before_boundary_scroll = pane.pdf.?.document_scroll_y;
+    const page0_revision = boundary.images[0].?.native.revision;
+    const page1_revision = boundary.images[1].?.native.revision;
+
+    // A scroll can activate the already-cached neighbor before the shell's
+    // next draw. Every consumer resolves the active page's resident raster,
+    // so a queued click cannot accidentally use page zero's dimensions.
+    pane.pdf.?.document_scroll_y = @as(f64, @floatFromInt(pane.pdf.?.page_starts[1])) - 0.5;
+    try std.testing.expectEqual(
+        page0_revision,
+        panes.Pdf.rasterForPage(&pane.pdf.?, 0).?.revision,
+    );
+    try std.testing.expect(panes.Pdf.scrollPane(p, pane, 1));
+    try std.testing.expectEqual(@as(usize, 1), pane.pdf.?.page);
+    try std.testing.expectEqual(
+        page1_revision,
+        panes.Pdf.rasterForPage(&pane.pdf.?, pane.pdf.?.page).?.revision,
+    );
+    panes.Pdf.activatePage(p, pane, 0, false);
+    pane.pdf.?.document_scroll_y = before_boundary_scroll;
+
+    p.update(.{ .key = .{ .cp = 'j' } });
+    try std.testing.expectEqual(before_boundary_scroll + p.cell_pixels.h, pane.pdf.?.document_scroll_y);
+    _ = frame.reset(.retain_capacity);
+    const second = try p.render(frame.allocator());
+    try std.testing.expectEqual(@as(usize, 2), second.nimages);
+    try std.testing.expectEqual(page0_revision, second.images[0].?.native.revision);
+    try std.testing.expectEqual(page1_revision, second.images[1].?.native.revision);
+    p.update(.{ .key = .{ .cp = 'k' } });
+    try std.testing.expectEqual(before_boundary_scroll, pane.pdf.?.document_scroll_y);
+
+    // Once page zero is wholly outside the viewport, both its owned RGBA and
+    // backend placement disappear; returning later renders a new raster. What
+    // does NOT go back is the memory: the departing page's bytes are parked in
+    // the relay and the arriving page of the same size takes them, so a fling
+    // never asks the allocator (or the kernel's fault handler) for megabytes it
+    // just gave up.
+    panes.Pdf.setPage(p, pane, 1);
+    _ = frame.reset(.retain_capacity);
+    const away = try p.render(frame.allocator());
+    try std.testing.expect(away.nimages > 0);
+    for (away.images[0..away.nimages]) |maybe| if (maybe) |place|
+        try std.testing.expect(place.native.page != 0);
+    try std.testing.expect(panes.Pdf.rasterForPage(&pane.pdf.?, 0) == null);
+    try std.testing.expectEqual(@as(usize, 1), pane.pdf.?.spare_len);
+    const retired = pane.pdf.?.spare[0];
+    panes.Pdf.setPage(p, pane, 0);
+    _ = frame.reset(.retain_capacity);
+    const returned = try p.render(frame.allocator());
+    try std.testing.expectEqual(@as(u32, 0), returned.images[0].?.native.page);
+    try std.testing.expectEqual(retired.ptr, returned.images[0].?.rgba.ptr);
+    try std.testing.expect(returned.images[0].?.native.revision != page0_revision);
+
+    // PdfFit exists as a real builtin in this build. It resets placement but
+    // preserves the current page pixels; fit-height j/k remains continuous in
+    // the same document-pixel coordinate space.
+    const fit_builtin = std.meta.stringToEnum(Builtin, "PdfFit") orelse
+        return error.MissingPdfFitBuiltin;
+    const revision_before_toggle = panes.Pdf.rasterForPage(
+        &pane.pdf.?,
+        pane.pdf.?.page,
+    ).?.revision;
+    try std.testing.expect(pardes.test_api.runBuiltin(
+        p,
+        @tagName(fit_builtin),
+        0,
+        "",
+        null,
+    ));
+    try std.testing.expectEqual(PdfFitMode.height, pane.pdf.?.fit);
+    try std.testing.expectEqual(@as(u16, 0), pane.pdf.?.pan_x);
+    try std.testing.expectEqual(@as(u16, 0), pane.pdf.?.pan_y);
+    try std.testing.expectEqual(
+        revision_before_toggle,
+        panes.Pdf.rasterForPage(&pane.pdf.?, pane.pdf.?.page).?.revision,
+    );
+    const height_tag = try pardes.test_api.tagText(p, p.scratch.allocator(), pane);
+    try std.testing.expect(std.mem.indexOf(u8, height_tag, "pdf 1/") != null);
+    try std.testing.expect(std.mem.indexOf(u8, height_tag, " width ") == null);
+    try std.testing.expect(std.mem.indexOf(u8, height_tag, " height ") != null);
+    try std.testing.expect(std.mem.indexOf(u8, height_tag, "PdfFit") != null);
+    for (p.panes) |slot| {
+        const other = slot orelse continue;
+        if (hasPdf(other)) continue;
+        panes.Pdf.toggleFit(other); // pane-scoped and deliberately inert here
+        try std.testing.expectEqual(PdfFitMode.height, pane.pdf.?.fit);
+        break;
+    }
+
+    // A fit-height landscape page exposes horizontal overflow to a horizontal
+    // wheel without rerasterizing. Use synthetic dimensions only for the
+    // geometry check; no frame is drawn while they differ from the buffer.
+    const active_raster = panes.Pdf.rasterForPage(&pane.pdf.?, pane.pdf.?.page).?;
+    const saved_iw = active_raster.iw;
+    const saved_ih = active_raster.ih;
+    active_raster.iw = 2000;
+    active_raster.ih = 500;
+    panes.Pdf.horizontalWheel(p, pane, 1);
+    try std.testing.expect(pane.pdf.?.pan_x > 0);
+    try std.testing.expectEqual(revision_before_toggle, active_raster.revision);
+    pane.pdf.?.pan_x = 0;
+    p.update(.{ .key = .{ .cp = '2' } });
+    p.update(.{ .key = .{ .cp = 'l' } });
+    try std.testing.expect(pane.pdf.?.pan_x > 0);
+    p.update(.{ .key = .{ .cp = '$' } });
+    try std.testing.expectEqual(std.math.maxInt(u16), pane.pdf.?.pan_x);
+    p.update(.{ .key = .{ .cp = '2' } });
+    p.update(.{ .key = .{ .cp = 'h' } });
+    try std.testing.expect(pane.pdf.?.pan_x < std.math.maxInt(u16));
+    p.update(.{ .key = .{ .cp = '0' } });
+    try std.testing.expectEqual(@as(u16, 0), pane.pdf.?.pan_x);
+    p.update(.{ .key = .{ .cp = 'g' } });
+    p.update(.{ .key = .{ .cp = 'l' } });
+    try std.testing.expectEqual(std.math.maxInt(u16), pane.pdf.?.pan_x);
+    p.update(.{ .key = .{ .cp = 'g' } });
+    p.update(.{ .key = .{ .cp = 'h' } });
+    try std.testing.expectEqual(@as(u16, 0), pane.pdf.?.pan_x);
+    active_raster.iw = saved_iw;
+    active_raster.ih = saved_ih;
+    pane.pdf.?.pan_x = 0;
+
+    const before_height_scroll = pane.pdf.?.document_scroll_y;
+    p.update(.{ .key = .{ .cp = 'j' } });
+    try std.testing.expect(pane.pdf.?.document_scroll_y > before_height_scroll);
+
+    const revision_before_search = active_raster.revision;
+    try p.runSearch(0, "Pardes", .text, .top);
+    try std.testing.expectEqualStrings("Pardes", pane.pdf.?.search_query);
+    try std.testing.expectEqual(revision_before_search, active_raster.revision);
+    const results_id = pane.search_pane orelse return error.MissingPdfSearchResults;
+    const results = p.panes[results_id].?.file.?.content;
+    try std.testing.expect(std.mem.indexOf(u8, results, "design.pdf:") != null);
+    // n SELECTS the first result row and opens nothing: the walk's only list
+    // here is the unlooked +Search buffer, so focus lands THERE. Enter is what
+    // jumps, and the document query survives both.
+    p.update(.{ .key = .{ .cp = 'n' } });
+    try std.testing.expectEqual(results_id, p.active);
+    const results_pane = p.panes[results_id].?;
+    try std.testing.expect(results_pane.vsel.active and results_pane.vsel.explicit);
+    try std.testing.expectEqual(@as(i32, 0), results_pane.cur_row);
+    try std.testing.expectEqual(@as(i32, 0), results_pane.cur_col);
+    p.update(.{ .key = .{ .cp = Key.enter } });
+    try std.testing.expectEqual(@as(usize, 0), p.active);
+    try std.testing.expectEqualStrings("Pardes", pane.pdf.?.search_query);
+
+    // Search state is owned and untruncated, and changing pages invalidates
+    // only page-local state while retaining the document query.
+    const long_query = "a query deliberately longer than any tag display budget: " ++
+        "012345678901234567890123456789012345678901234567890123456789" ++
+        "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
+    try pane.pdf.?.setSearchQuery(p.pdf_gpa, long_query);
+    try std.testing.expectEqualStrings(long_query, pane.pdf.?.search_query);
+    const next_page = if (pane.pdf.?.page == 0) @as(usize, 1) else 0;
+    panes.Pdf.setPage(p, pane, next_page);
+    try std.testing.expectEqualStrings(long_query, pane.pdf.?.search_query);
+
+    // PDF dumps intentionally retain the existing image-compatible schema:
+    // page/path and the exact editable tail are restored, while pane-local
+    // tint starts from the fresh-PDF default rather than being serialized.
+    panes.Pdf.toggleTint(pane);
+    try std.testing.expectEqual(PdfTintMode.full, pane.pdf.?.tint);
+    pane.pdf.?.fit = .height;
+    const custom_tail = " Keep Del";
+    @memcpy(pane.tag_tail[0..custom_tail.len], custom_tail);
+    pane.tag_tail_len = custom_tail.len;
+    pane.tag_init = true;
+    try p.dumpState();
+    const restored = try Pardes.initFromDump(gpa, .{}, p.dump_out.?);
+    defer restored.deinit();
+    try std.testing.expect(hasPdf(restored.panes[0].?));
+    try std.testing.expectEqual(pane.pdf.?.page, restored.panes[0].?.pdf.?.page);
+    try std.testing.expectEqual(PdfFitMode.width, restored.panes[0].?.pdf.?.fit);
+    try std.testing.expectEqual(PdfTintMode.filtered, restored.panes[0].?.pdf.?.tint);
+    const restored_pane = restored.panes[0].?;
+    try std.testing.expect(restored_pane.tag_init);
+    try std.testing.expectEqualStrings(
+        custom_tail,
+        restored_pane.tag_tail[0..restored_pane.tag_tail_len],
+    );
+}
+
+test "a fling's banded pages show the reader exactly what whole pages would" {
+    if (!pdf_enabled or platform == .web) return;
+
+    // The contract fast scrolling is allowed to change: HOW pixels are carried
+    // (a strip of a page instead of the page) but never WHICH pixels arrive. So
+    // the same frame is drawn twice — once at fling speed, once at reading
+    // speed — and every pixel inside every source rectangle must match, along
+    // with where on screen it goes.
+    const gpa = std.testing.allocator;
+    const p = try Pardes.init(gpa, .{ .file = "docs/design.pdf", .cols = 120, .rows = 40 });
+    defer p.deinit();
+    p.native_images = true;
+    const pane = p.panes[0].?;
+    const pv = &pane.pdf.?;
+    var frame = std.heap.ArenaAllocator.init(gpa);
+    defer frame.deinit();
+    _ = try p.render(frame.allocator());
+
+    const viewport = panes.Pdf.paneViewport(p, pane) orelse return error.MissingPdfViewport;
+    // Land mid-page-boundary so the frame carries TWO pages, each showing a
+    // fraction of itself — the shape a fling actually produces.
+    const landing = @as(f64, @floatFromInt(pv.page_starts[1] -| viewport.pixel_h / 3));
+    const Shot = struct {
+        page: u32,
+        dst: image.PixelRect,
+        pixels: []u8,
+    };
+    var shots: [8]Shot = undefined;
+    var shots_len: usize = 0;
+    defer for (shots[0..shots_len]) |shot| gpa.free(shot.pixels);
+
+    // A fling: one frame's worth of wheel travel carrying the viewport more
+    // than a screenful, delivered through the real scroll path so the distance
+    // is counted the way a wheel batch counts it.
+    pv.document_scroll_y = 0;
+    pv.scroll_travel = 0;
+    try std.testing.expect(panes.Pdf.scrollPane(p, pane, landing));
+    _ = frame.reset(.retain_capacity);
+    const flung = try p.render(frame.allocator());
+    try std.testing.expect(flung.nimages >= 2);
+    var banded = false;
+    for (flung.images[0..flung.nimages]) |maybe| {
+        const place = maybe orelse continue;
+        const geometry = place.native.geometry orelse return error.MissingPdfGeometry;
+        const raster = panes.Pdf.rasterForPage(pv, place.native.page) orelse
+            return error.MissingPdfRaster;
+        if (raster.band_h < raster.ih) banded = true;
+        try std.testing.expectEqual(place.iw * raster.band_h * 4, place.rgba.len);
+        shots[shots_len] = .{
+            .page = place.native.page,
+            .dst = geometry.dst,
+            .pixels = try copySourceRect(gpa, place, geometry.src),
+        };
+        shots_len += 1;
+    }
+    // ...and it really did band, or the comparison below is two identical
+    // whole-page renders agreeing with each other.
+    try std.testing.expect(banded);
+    // ...at reading speed: no travel at all since the frame above, so every
+    // page is rasterized whole again, and that is the picture the banded frame
+    // has to have matched.
+    _ = frame.reset(.retain_capacity);
+    const rested = try p.render(frame.allocator());
+    try std.testing.expectEqual(shots_len, rested.nimages);
+    for (rested.images[0..rested.nimages], shots[0..shots_len]) |maybe, shot| {
+        const place = maybe orelse return error.MissingPdfPlacement;
+        const geometry = place.native.geometry orelse return error.MissingPdfGeometry;
+        const raster = panes.Pdf.rasterForPage(pv, place.native.page) orelse
+            return error.MissingPdfRaster;
+        try std.testing.expectEqual(raster.ih, raster.band_h); // promoted at rest
+        try std.testing.expectEqual(shot.page, place.native.page);
+        try std.testing.expectEqual(shot.dst.x, geometry.dst.x);
+        try std.testing.expectEqual(shot.dst.y, geometry.dst.y);
+        try std.testing.expectEqual(shot.dst.w, geometry.dst.w);
+        try std.testing.expectEqual(shot.dst.h, geometry.dst.h);
+        const whole = try copySourceRect(gpa, place, geometry.src);
+        defer gpa.free(whole);
+        try std.testing.expectEqualSlices(u8, shot.pixels, whole);
+    }
+}
+
+/// The pixels a backend samples out of one placement: the source rectangle,
+/// row by row, at the texture's own stride. Test-only, and the one operation
+/// that makes "same picture" mean something when the textures differ in shape.
+fn copySourceRect(
+    gpa: std.mem.Allocator,
+    place: ImagePlace,
+    src: image.PixelRect,
+) ![]u8 {
+    const stride = place.iw * 4;
+    const row_len = @as(usize, src.w) * 4;
+    const out = try gpa.alloc(u8, row_len * src.h);
+    errdefer gpa.free(out);
+    var row: usize = 0;
+    while (row < src.h) : (row += 1) {
+        const from = (@as(usize, src.y) + row) * stride + @as(usize, src.x) * 4;
+        @memcpy(out[row * row_len ..][0..row_len], place.rgba[from..][0..row_len]);
+    }
+    return out;
+}
+
+test "PDF normal adapter consumes unsupported actions and navigates page fallback" {
+    if (!pdf_enabled or platform == .web) return;
+
+    const p = try Pardes.init(std.testing.allocator, .{
+        .file = "docs/design.pdf",
+        .cols = 80,
+        .rows = 24,
+    });
+    defer p.deinit();
+    const pane = p.panes[0].?;
+    const pv = &pane.pdf.?;
+    try std.testing.expect(pv.page_count > 3);
+    p.native_images = false;
+
+    // Every vertical vocabulary falls back to counted page changes when the
+    // shell cannot place native pixels.
+    p.update(.{ .key = .{ .cp = '2' } });
+    p.update(.{ .key = .{ .cp = 'j' } });
+    try std.testing.expectEqual(@as(usize, 2), pv.page);
+    p.update(.{ .key = .{ .cp = '2' } });
+    p.update(.{ .key = .{ .cp = 'k' } });
+    try std.testing.expectEqual(@as(usize, 0), pv.page);
+    p.update(.{ .key = .{ .cp = '2' } });
+    p.update(.{ .key = .{ .cp = 'd', .ctrl = true } });
+    try std.testing.expectEqual(@as(usize, 2), pv.page);
+    p.update(.{ .key = .{ .cp = '2' } });
+    p.update(.{ .key = .{ .cp = 'u', .ctrl = true } });
+    try std.testing.expectEqual(@as(usize, 0), pv.page);
+    p.update(.{ .key = .{ .cp = '2' } });
+    p.update(.{ .key = .{ .cp = 'f', .ctrl = true } });
+    try std.testing.expectEqual(@as(usize, 2), pv.page);
+    p.update(.{ .key = .{ .cp = '2' } });
+    p.update(.{ .key = .{ .cp = 'b', .ctrl = true } });
+    try std.testing.expectEqual(@as(usize, 0), pv.page);
+
+    // Prefix actions and the counted text goto-line action map to pages.
+    p.update(.{ .key = .{ .cp = 'g' } });
+    p.update(.{ .key = .{ .cp = 'e' } });
+    try std.testing.expectEqual(pv.page_count - 1, pv.page);
+    p.update(.{ .key = .{ .cp = 'g' } });
+    p.update(.{ .key = .{ .cp = 'g' } });
+    try std.testing.expectEqual(@as(usize, 0), pv.page);
+    p.update(.{ .key = .{ .cp = '3' } });
+    p.update(.{ .key = .{ .cp = 'g' } });
+    p.update(.{ .key = .{ .cp = 'g' } });
+    try std.testing.expectEqual(@as(usize, 2), pv.page);
+    p.update(.{ .key = .{ .cp = '2' } });
+    p.update(.{ .key = .{ .cp = 'G' } });
+    try std.testing.expectEqual(@as(usize, 1), pv.page);
+
+    // Editing/selection actions are consumed no-ops: parser state clears,
+    // placeholder cells never acquire a range, and PDF state stays intact.
+    const page_before_noop = pv.page;
+    const revision_before_noop = pv.next_raster_revision;
+    p.update(.{ .key = .{ .cp = '4' } });
+    p.update(.{ .key = .{ .cp = 'd' } });
+    p.update(.{ .key = .{ .cp = 'v' } });
+    p.update(.{ .key = .{ .cp = '|' } });
+    try std.testing.expectEqual(page_before_noop, pv.page);
+    try std.testing.expectEqual(revision_before_noop, pv.next_raster_revision);
+    try std.testing.expectEqual(@as(u32, 0), pane.normal.count);
+    try std.testing.expectEqual(.none, pane.normal.prefix);
+    try std.testing.expect(!pane.vsel.active and !pane.msel.active and pane.nsel == 0);
+    try std.testing.expect(!pane.tag_edit);
+
+    // Cross-pane BODY-NORMAL actions keep their established shared paths.
+    p.update(.{ .key = .{ .cp = ':' } });
+    try std.testing.expect(pane.tag_edit);
+    try std.testing.expectEqual(Mode.normal, pane.mode);
+    p.update(.{ .key = .{ .cp = Key.escape } });
+    try std.testing.expect(!pane.tag_edit);
+    p.update(.{ .key = .{ .cp = ' ' } });
+    try std.testing.expect(p.leader_on);
+    p.update(.{ .key = .{ .cp = '!' } });
+    try std.testing.expect(!p.leader_on);
+    p.update(.{ .key = .{ .cp = '/' } });
+    try std.testing.expect(pane.tag_edit);
+    p.update(.{ .key = .{ .cp = Key.escape } });
+    try std.testing.expect(!pane.tag_edit);
+}
+
+test "Escape cancels PDF chrome in place and Shift-Escape leaves the pane" {
+    if (!pdf_enabled or platform == .web) return;
+
+    const gpa = std.testing.allocator;
+    const p = try Pardes.init(gpa, .{
+        .file = "docs/design.pdf",
+        .cols = 80,
+        .rows = 28,
+    });
+    defer p.deinit();
+    const pane = p.panes[0].?;
+    const pv = &pane.pdf.?;
+    p.native_images = true;
+
+    // A second pane, then focus it and come back: `Last` has somewhere to go
+    // and the PDF is where the keys land.
+    panes.Pdf.openSections(p, 0);
+    p.update(.{ .key = .{ .cp = 'w', .ctrl = true } });
+    p.update(.{ .key = .{ .cp = 'j' } });
+    try std.testing.expectEqual(@as(usize, 1), p.active);
+    p.update(.{ .key = .{ .cp = 'w', .ctrl = true } });
+    p.update(.{ .key = .{ .cp = 'k' } });
+    try std.testing.expectEqual(@as(usize, 0), p.active);
+
+    // Everything a reader can see over the page: a search overlay and a live
+    // word selection.
+    try pv.setSearchQuery(p.pdf_gpa, "Pardes");
+    var found = try pv.document.search(gpa, pv.page, "Pardes");
+    defer found.deinit(gpa);
+    try std.testing.expect(found.quads.len > 0);
+    const quad = found.quads[0].quad;
+    try std.testing.expectEqual(
+        panes.Pdf.SelectionUpdate.changed,
+        pv.setSelection(p.pdf_gpa, quad.ul, quad.lr, false),
+    );
+    p.update(.{ .key = .{ .cp = '3' } });
+    const page_before = pv.page;
+    const scroll_before = pv.document_scroll_y;
+
+    // Escape drops the overlay and the selection, keeps the reading position,
+    // and does NOT hand the keyboard to another pane.
+    p.update(.{ .key = .{ .cp = Key.escape } });
+    try std.testing.expectEqual(@as(usize, 0), p.active);
+    try std.testing.expect(pv.selection == null and pv.selection_text.len == 0);
+    try std.testing.expectEqual(@as(usize, 0), pv.search_query.len);
+    try std.testing.expect(pv.search_results == null);
+    try std.testing.expect(!pv.highlights_dirty and !pv.search_reveal_pending);
+    try std.testing.expectEqual(page_before, pv.page);
+    try std.testing.expectEqual(scroll_before, pv.document_scroll_y);
+    try std.testing.expectEqual(@as(u32, 0), pane.normal.count);
+    try std.testing.expectEqual(.none, pane.normal.prefix);
+    // A second Escape on a bare document is inert rather than an exit.
+    p.update(.{ .key = .{ .cp = Key.escape } });
+    try std.testing.expectEqual(@as(usize, 0), p.active);
+
+    // Shift-Escape is the way out, and it leaves the document as it found it.
+    p.update(.{ .key = .{ .cp = Key.escape, .shift = true } });
+    try std.testing.expectEqual(@as(usize, 1), p.active);
+    try std.testing.expectEqual(page_before, pv.page);
+    try std.testing.expectEqual(scroll_before, pv.document_scroll_y);
+}
+
+test "PDF continuous strip renders every intersecting short page" {
+    if (!pdf_enabled or platform == .web) return;
+
+    const gpa = std.testing.allocator;
+    const p = try Pardes.init(gpa, .{
+        .file = "docs/design.pdf",
+        .cols = 80,
+        .rows = 24,
+    });
+    defer p.deinit();
+    const pane = p.panes[0].?;
+    const pv = &pane.pdf.?;
+    try std.testing.expect(pv.page_count > 3);
+    p.native_images = true;
+
+    // A legal wide MediaBox can make more than three pages intersect one
+    // viewport. Seed tiny matching rasters so this tests transport/cache
+    // cardinality without spending the unit test rendering fake page sizes.
+    for (pv.page_sizes) |*size| size.* = .{ .width = 100_000, .height = 1 };
+    pv.layout_valid = false;
+    pv.scroll_to_page_pending = true;
+    const viewport = panes.Pdf.ensurePaneLayout(p, pane).?;
+    const visible = panes.Pdf.visiblePages(pv, viewport);
+    try std.testing.expectEqual(pv.page_count, visible.len);
+    const request = panes.Pdf.renderRequest(viewport, pdf_raster_policy);
+    try std.testing.expect(pv.page_count <= pv.rasters.len);
+    for (0..pv.page_count) |page| {
+        const rgba = try gpa.alloc(u8, @as(usize, viewport.pixel_w) * 4);
+        @memset(rgba, @intCast(page));
+        pv.rasters[pv.rasters_len] = .{
+            .valid = true,
+            .page = page,
+            .rgba = rgba,
+            .iw = viewport.pixel_w,
+            .ih = 1,
+            .request = request,
+            .request_valid = true,
+            .tried = true,
+            .tint_key = .{ .mode = pv.tint, .colors = panes.Pdf.tintColors(p) },
+            .revision = @intCast(page + 1),
+        };
+        pv.rasters_len += 1;
+    }
+
+    var frame = std.heap.ArenaAllocator.init(gpa);
+    defer frame.deinit();
+    const surface = try p.render(frame.allocator());
+    try std.testing.expectEqual(pv.page_count, surface.nimages);
+    try std.testing.expectEqual(pv.page_count, pv.rasters_len);
+    for (surface.images[0..surface.nimages], 0..) |maybe, page| {
+        const place = maybe orelse return error.MissingShortPdfPage;
+        try std.testing.expectEqual(@as(u32, @intCast(page)), place.native.page);
+        try std.testing.expectEqual(@as(u32, 1), place.native.geometry.?.dst.h);
+    }
+}
+
+test "PdfTint cycles pane-local state and exposes it in the live PDF tag" {
+    if (!pdf_enabled or platform == .web) return;
+
+    const p = try Pardes.init(std.testing.allocator, .{
+        .file = "docs/design.pdf",
+        .cols = 80,
+        .rows = 24,
+    });
+    defer p.deinit();
+    const pane = p.panes[0].?;
+    const pv = &pane.pdf.?;
+    const tint_builtin = std.meta.stringToEnum(Builtin, "PdfTint") orelse
+        return error.MissingPdfTintBuiltin;
+
+    try std.testing.expectEqual(PdfTintMode.filtered, pv.tint);
+    const initial_tag = try pardes.test_api.tagText(p, p.scratch.allocator(), pane);
+    try std.testing.expect(std.mem.indexOf(
+        u8,
+        initial_tag,
+        "width PdfFit filtered PdfTint",
+    ) != null);
+
+    try std.testing.expect(pardes.test_api.runBuiltin(
+        p,
+        @tagName(tint_builtin),
+        0,
+        "",
+        null,
+    ));
+    try std.testing.expectEqual(PdfTintMode.full, pv.tint);
+    const full_tag = try pardes.test_api.tagText(p, p.scratch.allocator(), pane);
+    try std.testing.expect(std.mem.indexOf(u8, full_tag, "full PdfTint") != null);
+
+    // Running the same pane-scoped word in a terminal cannot mutate the PDF
+    // next to it. A FILE boot is one pane now, so that terminal is asked for
+    // here rather than inherited from init.
+    _ = try p.newShell(1, "");
+    _ = layout.splitColumn(p, 0, 1, false);
+    pardes.test_api.sync(p); // rects for the new column, exactly as the two-pane boot did
+    try std.testing.expect(!hasPdf(p.panes[1].?));
+    try std.testing.expect(pardes.test_api.runBuiltin(
+        p,
+        @tagName(tint_builtin),
+        1,
+        "",
+        null,
+    ));
+    try std.testing.expectEqual(PdfTintMode.full, pv.tint);
+
+    try std.testing.expect(pardes.test_api.runBuiltin(
+        p,
+        @tagName(tint_builtin),
+        0,
+        "",
+        null,
+    ));
+    try std.testing.expectEqual(PdfTintMode.disabled, pv.tint);
+    const disabled_tag = try pardes.test_api.tagText(p, p.scratch.allocator(), pane);
+    try std.testing.expect(std.mem.indexOf(u8, disabled_tag, "disabled PdfTint") != null);
+    try std.testing.expect(pardes.test_api.runBuiltin(
+        p,
+        @tagName(tint_builtin),
+        0,
+        "",
+        null,
+    ));
+    try std.testing.expectEqual(PdfTintMode.filtered, pv.tint);
+    try std.testing.expectEqual(PdfFitMode.width, pv.fit);
+
+    // `dark` intentionally leaves page bg/fg null. PDF tint resolves those
+    // deterministically to its chrome colors rather than host defaults.
+    const dark_index = for (themes, 0..) |th, i| {
+        if (std.mem.eql(u8, th.name, "dark")) break i;
+    } else return error.MissingDarkTheme;
+    p.setThemeIndex(dark_index);
+    const colors = panes.Pdf.tintColors(p);
+    try std.testing.expectEqual(p.theme().tag_bg, colors.background);
+    try std.testing.expectEqual(p.theme().tag_fg, colors.foreground);
+}
+
+test "PDF tint and tinted theme changes rebuild every visible raster only" {
+    if (!pdf_enabled or platform == .web) return;
+
+    const gpa = std.testing.allocator;
+    const p = try Pardes.init(gpa, .{
+        .file = "docs/design.pdf",
+        .cols = 80,
+        .rows = 24,
+    });
+    defer p.deinit();
+    const pane = p.panes[0].?;
+    const pv = &pane.pdf.?;
+    p.native_images = true;
+    var frame = std.heap.ArenaAllocator.init(gpa);
+    defer frame.deinit();
+
+    _ = try p.render(frame.allocator());
+    const viewport = panes.Pdf.paneViewport(p, pane).?;
+    pv.document_scroll_y = @floatFromInt(pv.page_starts[1] -| viewport.pixel_h / 2);
+    _ = frame.reset(.retain_capacity);
+    const default_surface = try p.render(frame.allocator());
+    try std.testing.expectEqual(PdfTintMode.filtered, pv.tint);
+    try std.testing.expectEqual(@as(usize, 2), default_surface.nimages);
+    try std.testing.expectEqual(@as(usize, 2), pv.rasters_len);
+
+    const Snapshot = struct {
+        page: u32,
+        revision: u32,
+        geometry: image.NativeGeometry,
+        pixel_offset_y: f32,
+        iw: usize,
+        ih: usize,
+        checksum: u64,
+    };
+    const Capture = struct {
+        fn get(surface: *const Surface) ![2]Snapshot {
+            if (surface.nimages != 2) return error.UnexpectedVisiblePdfCount;
+            var out: [2]Snapshot = undefined;
+            for (&out, 0..) |*snapshot, i| {
+                const place = surface.images[i] orelse return error.MissingVisiblePdf;
+                snapshot.* = .{
+                    .page = place.native.page,
+                    .revision = place.native.revision,
+                    .geometry = place.native.geometry orelse return error.MissingPdfGeometry,
+                    .pixel_offset_y = place.native.pixel_offset_y,
+                    .iw = place.iw,
+                    .ih = place.ih,
+                    .checksum = std.hash.Wyhash.hash(0x5044_4654_494e_5421, place.rgba),
+                };
+            }
+            return out;
+        }
+
+        fn expectGeometry(before: [2]Snapshot, after: [2]Snapshot) !void {
+            for (before, after) |old, new| {
+                try std.testing.expectEqual(old.page, new.page);
+                try std.testing.expectEqual(old.geometry, new.geometry);
+                try std.testing.expectEqual(old.pixel_offset_y, new.pixel_offset_y);
+                try std.testing.expectEqual(old.iw, new.iw);
+                try std.testing.expectEqual(old.ih, new.ih);
+            }
+        }
+    };
+    const default_filtered = try Capture.get(default_surface);
+    for (pv.rasters[0..pv.rasters_len]) |raster|
+        try std.testing.expectEqual(PdfTintMode.filtered, raster.tint_key.?.mode);
+
+    const dark_index = for (themes, 0..) |th, i| {
+        if (std.mem.eql(u8, th.name, "dark")) break i;
+    } else return error.MissingDarkTheme;
+    p.setThemeIndex(dark_index);
+    for (pv.rasters[0..pv.rasters_len]) |raster| try std.testing.expect(!raster.tried);
+    _ = frame.reset(.retain_capacity);
+    const themed_surface = try p.render(frame.allocator());
+    const themed = try Capture.get(themed_surface);
+    try Capture.expectGeometry(default_filtered, themed);
+    for (default_filtered, themed) |old, new| {
+        try std.testing.expect(new.revision > old.revision);
+        try std.testing.expect(new.checksum != old.checksum);
+    }
+
+    // Chrome animation reads a separate palette. Its ticks must never disturb
+    // the target-theme tint key or ask MuPDF for the same pixels again.
+    try std.testing.expect(p.animationActive());
+    for (0..layout.Animation.transition_steps) |_| {
+        p.update(.tick);
+        _ = frame.reset(.retain_capacity);
+        const tick_surface = try p.render(frame.allocator());
+        const ticked = try Capture.get(tick_surface);
+        try Capture.expectGeometry(themed, ticked);
+        for (themed, ticked) |once, after_tick| {
+            try std.testing.expectEqual(once.revision, after_tick.revision);
+            try std.testing.expectEqual(once.checksum, after_tick.checksum);
+        }
+    }
+    try std.testing.expect(!p.animationActive());
+
+    panes.Pdf.toggleTint(pane);
+    try std.testing.expectEqual(PdfTintMode.full, pv.tint);
+    _ = frame.reset(.retain_capacity);
+    const full_surface = try p.render(frame.allocator());
+    const full = try Capture.get(full_surface);
+    try Capture.expectGeometry(themed, full);
+    for (themed, full) |old, new| {
+        try std.testing.expect(new.revision > old.revision);
+    }
+    for (pv.rasters[0..pv.rasters_len]) |raster|
+        try std.testing.expectEqual(PdfTintMode.full, raster.tint_key.?.mode);
+
+    panes.Pdf.toggleTint(pane);
+    try std.testing.expectEqual(PdfTintMode.disabled, pv.tint);
+    _ = frame.reset(.retain_capacity);
+    const disabled_surface = try p.render(frame.allocator());
+    const disabled = try Capture.get(disabled_surface);
+    try Capture.expectGeometry(full, disabled);
+    for (full, disabled) |old, source| {
+        try std.testing.expect(source.revision > old.revision);
+        try std.testing.expect(source.checksum != old.checksum);
+    }
+
+    const acme_index = for (themes, 0..) |th, i| {
+        if (std.mem.eql(u8, th.name, "acme")) break i;
+    } else return error.MissingAcmeTheme;
+    for (pv.rasters[0..pv.rasters_len]) |raster| try std.testing.expect(raster.tried);
+    p.setThemeIndex(acme_index);
+    // Disabled keys ignore theme colors, so neither explicit invalidation nor
+    // the per-raster key comparison asks MuPDF for replacement pixels.
+    for (pv.rasters[0..pv.rasters_len]) |raster| try std.testing.expect(raster.tried);
+    _ = frame.reset(.retain_capacity);
+    const unchanged_surface = try p.render(frame.allocator());
+    const unchanged = try Capture.get(unchanged_surface);
+    try Capture.expectGeometry(disabled, unchanged);
+    for (disabled, unchanged) |old, new| {
+        try std.testing.expectEqual(old.revision, new.revision);
+        try std.testing.expectEqual(old.checksum, new.checksum);
+    }
+    try std.testing.expectEqual(@as(usize, 2), pv.rasters_len);
+}
+
+test "PDF resize preserves page-relative document position" {
+    if (!pdf_enabled or platform == .web) return;
+
+    const gpa = std.testing.allocator;
+    const p = try Pardes.init(gpa, .{
+        .file = "docs/design.pdf",
+        .cols = 80,
+        .rows = 24,
+    });
+    defer p.deinit();
+    const pane = p.panes[0].?;
+    const pv = &pane.pdf.?;
+    p.native_images = true;
+    var frame = std.heap.ArenaAllocator.init(gpa);
+    defer frame.deinit();
+
+    panes.Pdf.setPage(p, pane, 1);
+    _ = try p.render(frame.allocator());
+    const fraction: f64 = 0.375;
+    pv.document_scroll_y = @as(f64, @floatFromInt(pv.page_starts[1])) +
+        fraction * @as(f64, @floatFromInt(pv.page_heights[1]));
+    p.update(.{ .resize = .{
+        .cols = 100,
+        .rows = 24,
+        .cell_pixels = p.cell_pixels,
+    } });
+    try std.testing.expect(!pv.layout_valid);
+    try std.testing.expect(pv.layout_anchor_pending);
+    _ = frame.reset(.retain_capacity);
+    _ = try p.render(frame.allocator());
+    const resized_fraction = (pv.document_scroll_y -
+        @as(f64, @floatFromInt(pv.page_starts[1]))) /
+        @as(f64, @floatFromInt(pv.page_heights[1]));
+    try std.testing.expectApproxEqAbs(fraction, resized_fraction, 0.000_001);
+    try std.testing.expectEqual(@as(usize, 1), pv.page);
+
+    const held = pv.document_scroll_y;
+    p.update(.{ .resize = .{
+        .cols = 100,
+        .rows = 24,
+        .cell_pixels = p.cell_pixels,
+    } });
+    try std.testing.expectEqual(held, pv.document_scroll_y);
+    try std.testing.expect(pv.layout_valid);
+}
+
+test "PDF pane geometry change preserves its page-relative position" {
+    if (!pdf_enabled or platform == .web) return;
+
+    const gpa = std.testing.allocator;
+    const p = try Pardes.init(gpa, .{
+        .file = "docs/design.pdf",
+        .cols = 80,
+        .rows = 24,
+    });
+    defer p.deinit();
+    // A FILE boot is one pane now and a lone column always fills the window,
+    // so the divider drag below needs a second column to take the width from.
+    _ = try p.newShell(1, "");
+    _ = layout.splitColumn(p, 0, 1, false);
+    pardes.test_api.sync(p); // rects for the new column, exactly as the two-pane boot did
+    const pane = p.panes[0].?;
+    const pv = &pane.pdf.?;
+    p.native_images = true;
+    var frame = std.heap.ArenaAllocator.init(gpa);
+    defer frame.deinit();
+
+    panes.Pdf.setPage(p, pane, 1);
+    _ = try p.render(frame.allocator());
+    const fraction: f64 = 0.625;
+    pv.document_scroll_y = @as(f64, @floatFromInt(pv.page_starts[1])) +
+        fraction * @as(f64, @floatFromInt(pv.page_heights[1]));
+    const old_width = pv.layout_viewport_w;
+
+    // A divider/split changes rects through computeGeom without emitting a
+    // shell resize. panes.Pdf.ensurePaneLayout anchors against the old layout
+    // before rebuilding it for this wider pane.
+    const sibling_weight = p.col_weight[1];
+    p.col_weight[0] = sibling_weight * 6;
+    layout.compute(p);
+    try std.testing.expect(panes.Pdf.paneViewport(p, pane).?.pixel_w != old_width);
+    try std.testing.expect(pv.layout_valid);
+    _ = frame.reset(.retain_capacity);
+    _ = try p.render(frame.allocator());
+    const changed_fraction = (pv.document_scroll_y -
+        @as(f64, @floatFromInt(pv.page_starts[1]))) /
+        @as(f64, @floatFromInt(pv.page_heights[1]));
+    try std.testing.expectApproxEqAbs(fraction, changed_fraction, 0.000_001);
+    try std.testing.expectEqual(@as(usize, 1), pv.page);
+
+    // An explicit pending reveal wins over an implicit layout anchor.
+    pv.page = 2;
+    pv.scroll_to_page_pending = true;
+    p.col_weight[0] = sibling_weight * 2;
+    layout.compute(p);
+    _ = frame.reset(.retain_capacity);
+    _ = try p.render(frame.allocator());
+    try std.testing.expectEqual(
+        @as(f64, @floatFromInt(pv.page_starts[2])),
+        pv.document_scroll_y,
+    );
+}
+
+test "PDF n/N addresses and reveals distinct MuPDF hits on one page" {
+    if (!pdf_enabled or platform == .web) return;
+
+    const gpa = std.testing.allocator;
+    const p = try Pardes.init(gpa, .{
+        .file = "docs/design.pdf",
+        .cols = 120,
+        .rows = 24,
+    });
+    defer p.deinit();
+    const pane = p.panes[0].?;
+    const pv = &pane.pdf.?;
+    p.native_images = true;
+
+    var page_hits = try pv.document.search(gpa, 0, "Pardes");
+    defer page_hits.deinit(gpa);
+    try std.testing.expect(page_hits.hit_count >= 3);
+
+    try p.runSearch(0, "Pardes", .text, .top);
+    const results_id = pane.search_pane orelse return error.MissingPdfSearchResults;
+    const rows = p.panes[results_id].?.file.?.content;
+    try std.testing.expect(std.mem.indexOf(u8, rows, "design.pdf:1:1 Pardes\n") != null);
+    try std.testing.expect(std.mem.indexOf(u8, rows, "design.pdf:1:2 Pardes\n") != null);
+    try std.testing.expect(std.mem.indexOf(u8, rows, "design.pdf:1:3 Pardes\n") != null);
+
+    // Exaggerate the cell aspect only to make the three fixture hits occupy
+    // distinct fit-width crops. The search/reveal math must use the same
+    // reported metrics as placement, whatever a backend reports.
+    p.update(.{ .resize = .{
+        .cols = p.screen_w,
+        .rows = p.screen_h,
+        .cell_pixels = .{ .w = 16, .h = 4 },
+    } });
+
+    var frame = std.heap.ArenaAllocator.init(gpa);
+    defer frame.deinit();
+    try std.testing.expect(pardes.test_api.searchStep(p, 0, 1));
+    try std.testing.expectEqual(@as(usize, 0), pv.search_hit);
+    const first = try p.render(frame.allocator());
+    const revision = first.images[0].?.native.revision;
+    const raster = panes.Pdf.rasterForPage(pv, pv.page).?;
+    const first_scroll = pv.document_scroll_y;
+    const first_results = pv.search_results orelse return error.MissingPdfPageSearch;
+    const first_quad = for (first_results.quads) |item| {
+        if (item.hit == 0) break item.quad;
+    } else return error.MissingFirstPdfHit;
+    const first_y = panes.Pdf.normalizedPixel(
+        (first_quad.ul.y + first_quad.ur.y + first_quad.ll.y + first_quad.lr.y) / 4,
+        raster.ih,
+    );
+    const first_geometry = panes.Pdf.paneGeometry(p, pane) orelse return error.MissingPdfGeometry;
+    try std.testing.expect(first_y >= first_geometry.src.y and
+        first_y < first_geometry.src.y + first_geometry.src.h);
+
+    try std.testing.expect(pardes.test_api.searchStep(p, 0, 1));
+    try std.testing.expectEqual(@as(usize, 1), pv.search_hit);
+    _ = frame.reset(.retain_capacity);
+    const second = try p.render(frame.allocator());
+    try std.testing.expectEqual(revision, second.images[0].?.native.revision);
+
+    try std.testing.expect(pardes.test_api.searchStep(p, 0, 1));
+    try std.testing.expectEqual(@as(usize, 2), pv.search_hit);
+    _ = frame.reset(.retain_capacity);
+    const third = try p.render(frame.allocator());
+    try std.testing.expectEqual(revision, third.images[0].?.native.revision);
+    try std.testing.expect(pv.document_scroll_y != first_scroll);
+    const third_results = pv.search_results orelse return error.MissingPdfPageSearch;
+    const third_quad = for (third_results.quads) |item| {
+        if (item.hit == 2) break item.quad;
+    } else return error.MissingThirdPdfHit;
+    const third_y = panes.Pdf.normalizedPixel(
+        (third_quad.ul.y + third_quad.ur.y + third_quad.ll.y + third_quad.lr.y) / 4,
+        raster.ih,
+    );
+    const third_geometry = panes.Pdf.paneGeometry(p, pane) orelse return error.MissingPdfGeometry;
+    try std.testing.expect(third_y >= third_geometry.src.y and
+        third_y < third_geometry.src.y + third_geometry.src.h);
+}
+
+test "PDF native mouse selection, Look, and highlights share page geometry" {
+    if (!pdf_enabled or platform == .web) return;
+
+    const gpa = std.testing.allocator;
+    const p = try Pardes.init(gpa, .{
+        .file = "docs/design.pdf",
+        .cols = 80,
+        .rows = 24,
+    });
+    defer p.deinit();
+    const pane = p.panes[0].?;
+    var frame = std.heap.ArenaAllocator.init(gpa);
+    defer frame.deinit();
+
+    // A host without Kitty/native pixels keeps the projected-text contract:
+    // j/k can still change pages and a body drag remains a generic selection.
+    const fallback = try p.render(frame.allocator());
+    try std.testing.expectEqual(@as(usize, 0), fallback.nimages);
+    p.update(.{ .key = .{ .cp = 'j' } });
+    try std.testing.expectEqual(@as(usize, 1), pane.pdf.?.page);
+    p.update(.{ .key = .{ .cp = 'k' } });
+    try std.testing.expectEqual(@as(usize, 0), pane.pdf.?.page);
+    const fallback_rect = p.rects[0];
+    const fallback_col = fallback_rect.x + config.GUTTER + 1;
+    const fallback_row = fallback_rect.y + BOX_H + 1;
+    p.update(.{ .mouse = .{ .button = config.select_button, .kind = .press, .col = fallback_col, .row = fallback_row } });
+    p.update(.{ .mouse = .{ .button = config.select_button, .kind = .drag, .col = fallback_col + 4, .row = fallback_row } });
+    p.update(.{ .mouse = .{ .button = config.select_button, .kind = .release, .col = fallback_col + 4, .row = fallback_row } });
+    try std.testing.expectEqual(.done, pane.sel[sel_slot].state);
+    try std.testing.expect(pane.pdf.?.selection == null);
+    pane.sel[sel_slot].state = .none;
+
+    p.native_images = true;
+    _ = frame.reset(.retain_capacity);
+    const plain = try p.render(frame.allocator());
+    const plain_revision = plain.images[0].?.native.revision;
+
+    var found = try pane.pdf.?.document.search(gpa, 0, "Pardes");
+    defer found.deinit(gpa);
+    const quad = found.quads[0].quad;
+    const nx = (quad.ul.x + quad.ur.x + quad.ll.x + quad.lr.x) / 4;
+    const ny = (quad.ul.y + quad.ur.y + quad.ll.y + quad.lr.y) / 4;
+    const pv = &pane.pdf.?;
+    const raster = panes.Pdf.rasterForPage(pv, pv.page).?;
+    const source_x: u32 = @intCast(@min(
+        raster.iw - 1,
+        @as(usize, @intFromFloat(nx * @as(f32, @floatFromInt(raster.iw)))),
+    ));
+    const source_y: u32 = @intCast(@min(
+        raster.ih - 1,
+        @as(usize, @intFromFloat(ny * @as(f32, @floatFromInt(raster.ih)))),
+    ));
+
+    // Bring the known word into the fit-width crop, then invert the shared
+    // source/destination geometry to the nearest body cell.
+    var geometry = panes.Pdf.paneGeometry(p, pane).?;
+    if (source_y < geometry.src.y or source_y >= geometry.src.y + geometry.src.h) {
+        const overflow = @as(u32, @intCast(raster.ih)) - geometry.src.h;
+        const wanted = @min(overflow, source_y -| geometry.src.h / 2);
+        pv.pan_y = if (overflow == 0) 0 else @intCast(
+            (@as(u64, wanted) * std.math.maxInt(u16) + overflow / 2) / overflow,
+        );
+        geometry = panes.Pdf.paneGeometry(p, pane).?;
+    }
+    const pixel_x = geometry.dst.x + @as(u32, @intCast(
+        @as(u64, source_x - geometry.src.x) * geometry.dst.w / geometry.src.w,
+    ));
+    const pixel_y = geometry.dst.y + @as(u32, @intCast(
+        @as(u64, source_y - geometry.src.y) * geometry.dst.h / geometry.src.h,
+    ));
+    const r = p.rects[0];
+    const base_col: i32 = @intCast(r.x + config.GUTTER + pixel_x / p.cell_pixels.w);
+    const base_row: i32 = @intCast(r.y + BOX_H + pixel_y / p.cell_pixels.h);
+
+    var selected_col: ?u16 = null;
+    var selected_row: u16 = 0;
+    const nearby = [_]i32{ 0, -1, 1, -2, 2 };
+    find_word: for (nearby) |dy| for (nearby) |dx| {
+        const col: u16 = @intCast(std.math.clamp(
+            base_col + dx,
+            @as(i32, r.x + config.GUTTER),
+            @as(i32, r.x + r.w - 1),
+        ));
+        const row: u16 = @intCast(std.math.clamp(
+            base_row + dy,
+            @as(i32, r.y + BOX_H),
+            @as(i32, r.y + r.h - 1),
+        ));
+        if (!panes.Pdf.beginSelection(p, pane, col, row)) continue;
+        if (std.ascii.indexOfIgnoreCase(pv.selection_text, "Pardes") != null) {
+            selected_col = col;
+            selected_row = row;
+            break :find_word;
+        }
+    };
+    const word_col = selected_col orelse return error.PdfMouseMappingMissedWord;
+    try std.testing.expect(std.ascii.indexOfIgnoreCase(
+        pardes.test_api.heldSelection(p, 0).?,
+        "Pardes",
+    ) != null);
+
+    _ = frame.reset(.retain_capacity);
+    const selected_frame = try p.render(frame.allocator());
+    const selected_revision = selected_frame.images[0].?.native.revision;
+    try std.testing.expect(selected_revision != plain_revision);
+
+    // Repeating an identical drag endpoint is a no-op: Kitty/SDL keep the
+    // same texture generation instead of retransmitting identical pixels.
+    try std.testing.expect(panes.Pdf.beginSelection(p, pane, word_col, selected_row));
+    try std.testing.expect(raster.tried);
+    _ = frame.reset(.retain_capacity);
+    const duplicate = try p.render(frame.allocator());
+    try std.testing.expectEqual(selected_revision, duplicate.images[0].?.native.revision);
+
+    // Delayed native hover retains independent quads/text and changes only
+    // presentation state. In particular it must not borrow the click path,
+    // whose page activation and persistent selection are intentional effects
+    // of a gesture rather than observation.
+    if (config.look_preview_delay_frames) |delay| {
+        const active_before = p.active;
+        const page_before = pv.page;
+        const scroll_before = pv.document_scroll_y;
+        const sels_before = pane.sel;
+        const cursor_before = .{ pane.cur_row, pane.cur_col };
+        const modal_before = .{ pane.msel, pane.vsel, pane.nsel };
+        const selection_before = pv.selection orelse return error.MissingPdfSelection;
+        const selection_quads_before = try gpa.dupe(pdf_impl.Quad, selection_before.quads);
+        defer gpa.free(selection_quads_before);
+        const selection_text_before = try gpa.dupe(u8, pv.selection_text);
+        defer gpa.free(selection_text_before);
+        const selection_anchor_before = pv.selection_anchor;
+        const selection_head_before = pv.selection_head;
+        const query_before = try gpa.dupe(u8, pv.search_query);
+        defer gpa.free(query_before);
+        const search_hit_before = pv.search_hit;
+        const jumps_before = .{ p.njumps, p.jcur, p.n_look_src };
+        const effects_before = p.effects_len;
+        try std.testing.expect(p.drag == .none);
+
+        const hover_motion = Event{ .mouse = .{
+            .button = .none,
+            .kind = .motion,
+            .col = word_col,
+            .row = selected_row,
+        } };
+        p.update(hover_motion);
+        try std.testing.expect(p.look_hover_wait != null);
+        for (0..delay) |_| p.update(.tick);
+        const hover = p.pdf_hover_preview orelse return error.MissingPdfHoverPreview;
+        try std.testing.expectEqual(@as(usize, 0), hover.probe.page);
+        try std.testing.expect(hover.probe.quads.len > 0);
+        try std.testing.expect(std.ascii.indexOfIgnoreCase(hover.probe.text, "Pardes") != null);
+        try std.testing.expect(p.look_hover_preview == null);
+        try std.testing.expect(p.look_hover_wait == null);
+
+        const decorated = try panes.Pdf.buildHighlights(
+            pv,
+            p.scratch.allocator(),
+            panes.Pdf.highlightInput(p, 0, pane),
+        );
+        const page_highlights = decorated.forPage(pv.page, pv.page);
+        try std.testing.expectEqual(pdf_impl.HighlightKind.custom, page_highlights[0].kind);
+        try std.testing.expectEqual(pdf_impl.HighlightKind.selection, page_highlights[page_highlights.len - 1].kind);
+        _ = frame.reset(.retain_capacity);
+        const hovered_frame = try p.render(frame.allocator());
+        const hovered_revision = hovered_frame.images[0].?.native.revision;
+        try std.testing.expect(hovered_revision != selected_revision);
+
+        p.update(.pointer_leave);
+        try std.testing.expect(p.pdf_hover_preview == null);
+        _ = frame.reset(.retain_capacity);
+        const unhovered_frame = try p.render(frame.allocator());
+        try std.testing.expect(unhovered_frame.images[0].?.native.revision != hovered_revision);
+
+        try std.testing.expectEqual(active_before, p.active);
+        try std.testing.expectEqual(page_before, pv.page);
+        try std.testing.expectEqual(scroll_before, pv.document_scroll_y);
+        try std.testing.expect(std.meta.eql(sels_before, pane.sel));
+        try std.testing.expectEqual(cursor_before, .{ pane.cur_row, pane.cur_col });
+        try std.testing.expect(std.meta.eql(modal_before, .{ pane.msel, pane.vsel, pane.nsel }));
+        const selection_after = pv.selection orelse return error.HoverDroppedPdfSelection;
+        try std.testing.expectEqualSlices(pdf_impl.Quad, selection_quads_before, selection_after.quads);
+        try std.testing.expectEqualStrings(selection_text_before, pv.selection_text);
+        try std.testing.expect(std.meta.eql(selection_anchor_before, pv.selection_anchor));
+        try std.testing.expect(std.meta.eql(selection_head_before, pv.selection_head));
+        try std.testing.expectEqualStrings(query_before, pv.search_query);
+        try std.testing.expectEqual(search_hit_before, pv.search_hit);
+        try std.testing.expectEqual(jumps_before, .{ p.njumps, p.jcur, p.n_look_src });
+        try std.testing.expectEqual(effects_before, p.effects_len);
+        try std.testing.expect(p.drag == .none);
+    }
+
+    // A native right-click resolves the same MuPDF-snapped word and feeds it
+    // to Look. Search highlights precede selection highlights so the live
+    // selection remains visually authoritative where they overlap.
+    p.update(.{ .mouse = .{ .button = config.look_button, .kind = .press, .col = word_col, .row = selected_row } });
+    p.update(.{ .mouse = .{ .button = config.look_button, .kind = .release, .col = word_col, .row = selected_row } });
+    try std.testing.expect(std.ascii.indexOfIgnoreCase(pv.search_query, "Pardes") != null);
+    pv.resolveSearch(p.pdf_gpa);
+    const highlights = (try panes.Pdf.buildHighlights(
+        pv,
+        p.scratch.allocator(),
+        panes.Pdf.highlightInput(p, 0, pane),
+    )).items;
+    try std.testing.expect(highlights.len > 1);
+    try std.testing.expectEqual(pdf_impl.HighlightKind.search, highlights[0].kind);
+    try std.testing.expectEqual(pdf_impl.HighlightKind.selection, highlights[highlights.len - 1].kind);
+    const revision_before_reveal = raster.revision;
+    const max_document_scroll = @as(f64, @floatFromInt(
+        pv.document_height -| panes.Pdf.paneViewport(p, pane).?.pixel_h,
+    ));
+    pv.document_scroll_y = max_document_scroll;
+    panes.Pdf.revealSearch(pv, panes.Pdf.paneViewport(p, pane).?, panes.Pdf.paneGeometry(p, pane));
+    const revealed_scroll = pv.document_scroll_y;
+    try std.testing.expect(revealed_scroll != max_document_scroll);
+    try std.testing.expectEqual(revision_before_reveal, raster.revision);
+    pv.document_scroll_y = max_document_scroll;
+    panes.Pdf.revealSearch(
+        pv,
+        panes.Pdf.paneViewport(p, pane).?,
+        panes.Pdf.paneGeometry(p, pane),
+    ); // one shot: subsequent manual pan stays put
+    try std.testing.expectEqual(max_document_scroll, pv.document_scroll_y);
+    pv.document_scroll_y = revealed_scroll;
+    _ = frame.reset(.retain_capacity);
+    const searched = try p.render(frame.allocator());
+    try std.testing.expect(searched.images[0].?.native.revision != selected_revision);
+
+    // Fit and viewport changes can crop a hit which was already revealed.
+    // Fit remains placement-only. SDL's physical-viewport quality request
+    // changes with a resize and therefore replaces pixels; Kitty's fixed,
+    // bandwidth-conscious request retains them.
+    const revision_before_geometry_change = searched.images[0].?.native.revision;
+    pv.search_reveal_pending = false;
+    panes.Pdf.toggleFit(pane);
+    try std.testing.expect(pv.search_reveal_pending);
+    pv.search_reveal_pending = false;
+    panes.Pdf.toggleFit(pane); // restore the reading-width geometry
+    try std.testing.expect(pv.search_reveal_pending);
+    pv.search_reveal_pending = false;
+    const original_cell_pixels = p.cell_pixels;
+    p.update(.{ .resize = .{
+        .cols = p.screen_w,
+        .rows = p.screen_h,
+        .cell_pixels = p.cell_pixels,
+    } });
+    try std.testing.expect(!pv.search_reveal_pending);
+    p.update(.{ .resize = .{
+        .cols = p.screen_w,
+        .rows = p.screen_h,
+        .cell_pixels = .{
+            .w = original_cell_pixels.w,
+            .h = original_cell_pixels.h + 1,
+        },
+    } });
+    try std.testing.expect(pv.search_reveal_pending);
+    _ = frame.reset(.retain_capacity);
+    const geometry_changed = try p.render(frame.allocator());
+    if (pdf_raster_policy.match_viewport)
+        try std.testing.expect(geometry_changed.images[0].?.native.revision !=
+            revision_before_geometry_change)
+    else
+        try std.testing.expectEqual(
+            revision_before_geometry_change,
+            geometry_changed.images[0].?.native.revision,
+        );
+    p.update(.{ .resize = .{
+        .cols = p.screen_w,
+        .rows = p.screen_h,
+        .cell_pixels = original_cell_pixels,
+    } });
+    _ = frame.reset(.retain_capacity);
+    _ = try p.render(frame.allocator());
+
+    // Unsupported text-selection actions are consumed by the PDF adapter:
+    // they neither invent a range over placeholder cells nor disturb the
+    // native MuPDF selection. The select-button's no-drag click still clears.
+    p.update(.{ .key = .{ .cp = 'v' } });
+    try std.testing.expect(pv.selection != null);
+    try std.testing.expect(!pane.vsel.active);
+    p.update(.{ .mouse = .{ .button = config.select_button, .kind = .press, .col = word_col, .row = selected_row } });
+    p.update(.{ .mouse = .{ .button = config.select_button, .kind = .release, .col = word_col, .row = selected_row } });
+    try std.testing.expect(pv.selection == null);
+    try std.testing.expect(panes.Pdf.beginSelection(p, pane, word_col, selected_row));
+
+    // Native drag events update MuPDF quads and copied text immediately, but
+    // keep the already transmitted page generation stable until release.
+    _ = frame.reset(.retain_capacity);
+    const before_drag = try p.render(frame.allocator());
+    const before_drag_revision = before_drag.images[0].?.native.revision;
+    const drag_col = @min(r.x + r.w - 1, word_col +| 12);
+    const drag_row = @min(r.y + r.h - 1, selected_row +| 4);
+    p.update(.{ .mouse = .{
+        .button = config.select_button,
+        .kind = .press,
+        .col = word_col,
+        .row = selected_row,
+    } });
+    p.update(.{ .mouse = .{
+        .button = config.select_button,
+        .kind = .drag,
+        .col = @min(drag_col, word_col +| 4),
+        .row = @min(drag_row, selected_row +| 2),
+    } });
+    _ = frame.reset(.retain_capacity);
+    const during_first_drag = try p.render(frame.allocator());
+    try std.testing.expectEqual(
+        before_drag_revision,
+        during_first_drag.images[0].?.native.revision,
+    );
+    p.update(.{ .mouse = .{
+        .button = config.select_button,
+        .kind = .drag,
+        .col = drag_col,
+        .row = drag_row,
+    } });
+    try std.testing.expect(p.drag.select.pdf.selection_changed);
+    _ = frame.reset(.retain_capacity);
+    const during_second_drag = try p.render(frame.allocator());
+    try std.testing.expectEqual(
+        before_drag_revision,
+        during_second_drag.images[0].?.native.revision,
+    );
+    p.update(.{ .mouse = .{
+        .button = config.select_button,
+        .kind = .release,
+        .col = drag_col,
+        .row = drag_row,
+    } });
+    try std.testing.expect(!raster.tried);
+    _ = frame.reset(.retain_capacity);
+    const committed_drag = try p.render(frame.allocator());
+    try std.testing.expectEqual(
+        before_drag_revision + 1,
+        committed_drag.images[0].?.native.revision,
+    );
+    _ = frame.reset(.retain_capacity);
+    const stable_drag = try p.render(frame.allocator());
+    try std.testing.expectEqual(
+        committed_drag.images[0].?.native.revision,
+        stable_drag.images[0].?.native.revision,
+    );
+
+    const saved_query = try gpa.dupe(u8, pv.search_query);
+    defer gpa.free(saved_query);
+    panes.Pdf.setPage(p, pane, 1);
+    try std.testing.expect(pv.selection == null);
+    try std.testing.expectEqual(@as(usize, 0), pv.selection_text.len);
+    try std.testing.expectEqualStrings(saved_query, pv.search_query);
+}
+
+test "Esc back into a PDF keeps the offset within its page" {
+    if (!pdf_enabled or platform == .web) return;
+    const gpa = std.testing.allocator;
+    var tmp = std.testing.tmpDir(.{});
+    defer tmp.cleanup();
+    const fixture = try pdf_impl.makeOutlineTestPdf(gpa);
+    defer gpa.free(fixture);
+    try tmp.dir.writeFile(std.testing.io, .{ .sub_path = "outline.pdf", .data = fixture });
+    var path_buf: [256]u8 = undefined;
+    const path = try std.fmt.bufPrint(&path_buf, ".zig-cache/tmp/{s}/outline.pdf", .{tmp.sub_path});
+
+    const p = try Pardes.init(gpa, .{ .file = path, .cols = 80, .rows = 28 });
+    defer p.deinit();
+    p.update(.{ .resize = .{ .cols = 80, .rows = 28 } });
+    const doc = p.active;
+    const dp = p.panes[doc].?;
+    try std.testing.expect(dp.pdf != null);
+    pardes.test_api.sync(p);
+
+    // Read a little way DOWN the page you are on, then step away.
+    const pv = &dp.pdf.?;
+    pv.document_scroll_y += 137;
+    const mid = pv.document_scroll_y;
+    pv.scroll_to_page_pending = false;
+    p.update(.{ .key = .{ .cp = 'n', .alt = true } }); // a shell under the doc
+    pardes.test_api.sync(p);
+    const shell = p.active;
+    try std.testing.expect(shell != doc);
+
+    p.update(.{ .key = .{ .cp = Key.escape } }); // Esc: back into the PDF
+    pardes.test_api.sync(p);
+    try std.testing.expectEqual(doc, p.active);
+
+    // The jumps stack records a PDF as its PAGE, so returning revealed the page
+    // you were already on — and a reveal sets `document_scroll_y` to that page's
+    // start, throwing away where you had read to inside it.
+    try std.testing.expectEqual(mid, pv.document_scroll_y);
+    // Same reveal, the other half: with no valid layout yet it only ARMS the
+    // snap, so a test that watched the offset alone would not see it coming.
+    try std.testing.expect(!pv.scroll_to_page_pending);
+}