Keep a pane's filesystem state on the Pane instead of a slot-indexed table

addr, limit, the event queue and its readers, pty/data's queue, a waiting
run and the /log announcement flag lived in p.fs.panes[slot], reset when
the pane went; a reused slot is how the bug class came in. acme keeps the
same state on its Window (editors/acme/dat.h:226-266), so now Pane.fs
holds it: announced, retired (noteRetire, which still answers a waiting
run and drops the listener count first) and freed with the pane itself.

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

3 files changed, 5 insertions, 5 deletions

diff --git a/test/fs_bench.zig b/test/fs_bench.zig
index 74b7b5da..00601ca3 100644
--- a/test/fs_bench.zig
+++ b/test/fs_bench.zig
@@ -285,7 +285,7 @@ pub fn main(init: std.process.Init) !void {
         const initial_bytes = pane.file.?.content.len;
         key_body_bytes = initial_bytes;
         if (scripted) {
-            keys.core.fs.panes[keys.file_id].readers = 1;
+            keys.core.panes[keys.file_id].?.fs.readers = 1;
             keys.core.fs.listeners = 1;
         }
         counting.allocations = 0;
@@ -297,7 +297,7 @@ pub fn main(init: std.process.Init) !void {
         const elapsed = nowNs() - start;
         if (pane.file.?.content.len != initial_bytes + key_reps or pane.cur_col != key_reps or
             !std.mem.allEqual(u8, pane.file.?.content[0..key_reps], 'x')) return error.MissingKeystroke;
-        const events = &keys.core.fs.panes[keys.file_id].events;
+        const events = &keys.core.panes[keys.file_id].?.fs.events;
         if (scripted) for (0..key_reps) |i| {
             var buf: [64]u8 = undefined;
             const expected = try std.fmt.bufPrint(&buf, "KI{d} {d} 0 1 x\n", .{ i, i + 1 });
diff --git a/test/output.zig b/test/output.zig
index 7c80e105..cda5f556 100644
--- a/test/output.zig
+++ b/test/output.zig
@@ -1082,7 +1082,7 @@ test "identical result refresh keeps warm content caches without allocation" {
         try std.testing.expectEqual(id, source.search_pane.?);
         try std.testing.expectEqual(@as(usize, 1), source.search_row.?);
         try std.testing.expectEqual(result.serial, p.look_walk_owner.?);
-        try std.testing.expect(p.fs.panes[id].events.empty());
+        try std.testing.expect(p.panes[id].?.fs.events.empty());
     }
 
     try panes.Output.fillResults(p, 0, "/tmp", .{ .query = .references }, "changed", try p.gpa.dupe(u8, "short\n"), null);
@@ -1099,7 +1099,7 @@ test "identical result refresh keeps warm content caches without allocation" {
     try std.testing.expectEqual(@as(usize, 0), file.scroll);
     try std.testing.expectEqual(@as(i32, 0), result.hscroll);
     try std.testing.expect(source.search_row == null);
-    const events = &p.fs.panes[id].events;
+    const events = &p.panes[id].?.fs.events;
     try std.testing.expect(std.mem.startsWith(u8, events.peek().?, "KD"));
     events.pop();
     try std.testing.expect(std.mem.startsWith(u8, events.peek().?, "KI"));
diff --git a/test/panes.zig b/test/panes.zig
index 2f307cb5..e865641f 100644
--- a/test/panes.zig
+++ b/test/panes.zig
@@ -946,7 +946,7 @@ const ClickCursorTests = struct {
         defer _ = pardes.ctlfs.handle(p, .{ .tag = 0, .op = .release, .node = event_node, .handle = opened.handle });
 
         for ([_]pardes.Mouse.Button{ .middle, .right }) |button| {
-            const events = &p.fs.panes[0].events;
+            const events = &p.panes[0].?.fs.events;
             while (!events.empty()) events.pop();
             click(p, button, x + 2, y + 2);
             const selected = events.peek() orelse return error.MissingSelectionGesture;