Restore keeps each pane's dot, as acme's dump does

A restored text pane came back with its caret at its view's top, whatever
had been selected. The dump now keeps each text pane's dot, q0 and q1 as
acme's keeps a window's, and Restore puts it back without moving the view
it kept. Two look-walk tests that restored and walked on now start from the
match they were on.

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

2 files changed, 32 insertions, 0 deletions

diff --git a/src/File.zig b/src/File.zig
index 929e33bf..6a1ac319 100644
--- a/src/File.zig
+++ b/src/File.zig
@@ -814,6 +814,14 @@ pub fn restore(p: *Pardes, id: usize, src: dump.Pane) !*Pane {
     pane.file.?.tree_context = saved.tree_context and supportsContext(pane);
     pane.body.cur_pinned = true;
     pane.body.cur_row = @intCast(src.scroll);
+    // Its dot as it was, where the view the dump kept shows it.
+    if (saved.dot) |dot| if (dot[0] <= dot[1] and dot[1] <= content.len) {
+        const a = modal.positionAt(content, dot[0]);
+        const h = modal.positionAt(content, if (dot[1] > dot[0]) modal.prevGrapheme(content, dot[1]) else dot[0]);
+        pane.body.vsel = .{ .active = dot[1] > dot[0], .row = @intCast(a.row), .col = @intCast(a.col), .explicit = true };
+        pane.body.cur_row = @intCast(h.row);
+        pane.body.cur_col = @intCast(h.col);
+    };
     pane.cols = @max(1, src.cols);
     pane.rows = @max(1, src.rows);
     if (output == null and filesystem.localPath(path) != null) p.emit(.{ .watch = .{ .pane = @intCast(id), .on = true, .mode = .baseline_disk } });
diff --git a/src/dump.zig b/src/dump.zig
index 5b0983ad..7101b708 100644
--- a/src/dump.zig
+++ b/src/dump.zig
@@ -142,6 +142,9 @@ pub const File = struct {
     origin_arg: []const u8 = "",
     mini_source: []const u8 = "",
     mini_colors_b64: []const u8 = "",
+    /// Its dot, q0 and q1 in bytes, as acme's dump keeps a window's; null
+    /// in older dumps.
+    dot: ?[2]u32 = null,
 };
 
 pub const ImagePalette = enum {
@@ -653,6 +656,10 @@ pub fn dumpState(p: *Pardes) !void {
         else
             try pardes.panes.Terminal.dumpPane(pane, arena, tag, body, scroll);
         dp.tag_tail = pane.tag.own;
+        if (dp.file) |*df| {
+            const dot = ctlfs.pane.dotOf(pane);
+            df.dot = .{ dot.q0, dot.q1 };
+        }
         dp.serial = pane.serial;
         dump_panes[panes_len] = dp;
         panes_len += 1;
@@ -918,3 +925,20 @@ test "a dump keeps the settings that differ from a fresh session's, and a restor
     try std.testing.expectEqual(config.Runtime.Placement.pardes, restored.settings.placement);
     try std.testing.expect(!restored.settings.verbose);
 }
+
+test "a restored pane keeps its dot, as acme's dump keeps a window's" {
+    const gpa = std.testing.allocator;
+    const p = try Pardes.init(gpa, .{ .tty_only = true });
+    defer p.deinit();
+    const pane = try p.setTestFile("one two three\nfour\n");
+    ctlfs.pane.setDot(pane, .{ .q0 = 4, .q1 = 7 });
+    try dumpState(p);
+    const restored = try initFromDump(gpa, .{ .tty_only = true }, p.dump_out.?);
+    defer restored.deinit();
+    const again = for (restored.panes) |slot| {
+        if (slot) |candidate| if (candidate.file != null) break candidate;
+    } else return error.FileLost;
+    const dot = ctlfs.pane.dotOf(again);
+    try std.testing.expectEqual(@as(u32, 4), dot.q0);
+    try std.testing.expectEqual(@as(u32, 7), dot.q1);
+}