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]>

1 files changed, 6 insertions, 6 deletions

diff --git a/src/ninep/addr.zig b/src/ninep/addr.zig
index 566e2364..e41d306e 100644
--- a/src/ninep/addr.zig
+++ b/src/ninep/addr.zig
@@ -247,13 +247,13 @@ test "the address language, form by form" {
 
     _ = th.wr(p, addr, "1");
     _ = th.wr(p, addr, ".");
-    try testing.expectEqual(@as(u32, 0), p.fs.panes[0].addr.q0);
-    try testing.expectEqual(@as(u32, 4), p.fs.panes[0].addr.q1);
+    try testing.expectEqual(@as(u32, 0), p.panes[0].?.fs.addr.q0);
+    try testing.expectEqual(@as(u32, 4), p.panes[0].?.fs.addr.q1);
 
     _ = th.wr(p, addr, "$");
     _ = th.wr(p, addr, "?o?");
-    try testing.expectEqual(@as(u32, 6), p.fs.panes[0].addr.q0); // the `o` in "two"
-    try testing.expectEqual(@as(u32, 7), p.fs.panes[0].addr.q1);
+    try testing.expectEqual(@as(u32, 6), p.panes[0].?.fs.addr.q0); // the `o` in "two"
+    try testing.expectEqual(@as(u32, 7), p.panes[0].?.fs.addr.q1);
 
     // limit is its own file: copying addr onto it bounds the search, and
     // truncating it lifts the bound again.
@@ -264,12 +264,12 @@ test "the address language, form by form" {
     const pair = th.rd(p, addr, 0, 64).bytes;
     @memcpy(copied[0..pair.len], pair);
     _ = th.wr(p, limit, copied[0..pair.len]);
-    try testing.expectEqual(@as(u32, 4), p.fs.panes[0].limit.?.q1);
+    try testing.expectEqual(@as(u32, 4), p.panes[0].?.fs.limit.?.q1);
     try testing.expectEqualStrings("          0           4 ", th.rd(p, limit, 0, 64).bytes);
     _ = th.wr(p, addr, "#0");
     try testing.expectEqual(E.INVAL, th.wr(p, addr, "/three/").errno());
     _ = th.call(p, .{ .tag = 6, .op = .setattr, .node = limit, .truncate = true });
-    try testing.expect(p.fs.panes[0].limit == null);
+    try testing.expect(p.panes[0].?.fs.limit == null);
     _ = th.wr(p, addr, "#0");
     try testing.expectEqual(Status.ok, th.wr(p, addr, "/three/").reply.status);