A look at a PDF's page past its last is a miss, "has no page N", never the last page in its place

manual.pdf:999 on a twelve-page PDF showed page 12 and said nothing,
so a stale or mistyped page number looked like a place found. It is
now the miss a line past a file's end is, whether the PDF is open (it
stays on its page) or not (nothing opens). A restore or a start-up page
past the end still lands on the last.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

2 files changed, 36 insertions, 2 deletions

diff --git a/test/mode.zig b/test/mode.zig
index 767cda93..f49c434c 100644
--- a/test/mode.zig
+++ b/test/mode.zig
@@ -109,7 +109,7 @@ test "Mode leaves image and PDF document modes unchanged" {
         const len = try tmp.dir.realPath(std.testing.io, &buffer);
         const path = try std.fmt.allocPrint(std.testing.allocator, "{s}/mode.pdf", .{buffer[0..len]});
         defer std.testing.allocator.free(path);
-        const document = try panes.Pdf.openPane(p, 2, path, 1);
+        const document = try panes.Pdf.openPane(p, 2, path, 1, .last);
         const page = document.pdf.?.page;
         try mode(p, 2, .normal);
         try std.testing.expectEqual(page, document.pdf.?.page);
diff --git a/test/pdf.zig b/test/pdf.zig
index 48869de1..36b3570e 100644
--- a/test/pdf.zig
+++ b/test/pdf.zig
@@ -343,7 +343,7 @@ test "PdfSections Look follows the exact owning PDF, not an equal path" {
     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);
+    const duplicate = try panes.Pdf.openPane(p, duplicate_id, path, 0, .last);
     pardes.exec.placeNew(p, 0, 0, duplicate_id, .doc);
     layout.compute(p);
     panes.Pdf.openSections(p, duplicate_id);
@@ -386,6 +386,40 @@ test "PdfSections caches an empty outline output" {
     try std.testing.expectEqual(serial, p.panes[output_id].?.serial);
 }
 
+test "a look at a PDF's page past its last is a miss, never the last 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.makeNoOutlineTestPdf(gpa);
+    defer gpa.free(fixture);
+    try tmp.dir.writeFile(std.testing.io, .{ .sub_path = "plain.pdf", .data = fixture });
+    try tmp.dir.writeFile(std.testing.io, .{ .sub_path = "other.pdf", .data = fixture });
+    var dir_buf: [4096]u8 = undefined;
+    const dir = dir_buf[0..try tmp.dir.realPath(std.testing.io, &dir_buf)];
+    var path_buf: [4200]u8 = undefined;
+    const path = try std.fmt.bufPrint(&path_buf, "{s}/plain.pdf", .{dir});
+    const p = try Pardes.init(gpa, .{ .file = path, .cols = 80, .rows = 28 });
+    defer p.deinit();
+    const doc = p.panes[0].?;
+    try std.testing.expect(doc.hasPdf());
+    var line: [4300]u8 = undefined;
+    // Open: it stays on its page.
+    const page = doc.pdf.?.page;
+    pardes.look.lookAt(p, 0, try std.fmt.bufPrint(&line, "{s}:999", .{path}));
+    try std.testing.expect(p.look_missed);
+    try std.testing.expectEqual(page, doc.pdf.?.page);
+    // Not open: nothing opens.
+    p.look_missed = false;
+    var before: usize = 0;
+    for (p.panes) |slot| before += @intFromBool(slot != null);
+    pardes.look.lookAt(p, 0, try std.fmt.bufPrint(&line, "{s}/other.pdf:999", .{dir}));
+    try std.testing.expect(p.look_missed);
+    var after: usize = 0;
+    for (p.panes) |slot| after += @intFromBool(slot != null);
+    try std.testing.expectEqual(before, after);
+}
+
 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,