A write to addr, limit or mark asks for no frame, so its close is not held behind one

Every write that changes a pane set needs_frame, an addr write too, so the editor drew a whole frame after each and the clunk that followed waited for the turn while it did: 0.5 ms (Debug) to 1.2 ms a clunk, what made addr and event write-back 4-10x acme's. An address, a limit and the mark flag are nothing drawn; their writes no longer ask for a frame. Clunk after an addr write: 0.518 -> 0.015 ms (Debug tty, fs.py client).

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

2 files changed, 18 insertions, 1 deletions

diff --git a/src/ninep/ctl.zig b/src/ninep/ctl.zig
index e7274c5e..b9268208 100644
--- a/src/ninep/ctl.zig
+++ b/src/ninep/ctl.zig
@@ -2428,6 +2428,20 @@ test "ctl reads acme's fields in acme's order, undo and redo flags included, the
     try testing.expectEqualStrings("1", f[9]);
 }
 
+test "a write to addr, limit or mark asks for no frame; one to body does" {
+    const p = try withFile(testing.allocator, "one\n");
+    defer p.deinit();
+    const serial = serialOf(p);
+    for ([_]tree.PaneFile{ .addr, .limit, .mark }) |file| {
+        p.needs_frame = false;
+        _ = p.serveFs(.{ .tag = 1, .op = .write, .node = Node.of(serial, file), .data = if (file == .mark) "1" else "#0" });
+        try testing.expect(!p.needs_frame);
+    }
+    p.needs_frame = false;
+    _ = p.serveFs(.{ .tag = 1, .op = .write, .node = Node.of(serial, .body), .data = "two\n" });
+    try testing.expect(p.needs_frame);
+}
+
 test "every EINVAL a write gets says why, in its err record too; DEL is a control character in a line" {
     const p = try withFile(testing.allocator, "x\n");
     defer p.deinit();
diff --git a/src/pardes.zig b/src/pardes.zig
index 391fa23d..c1b12a8b 100644
--- a/src/pardes.zig
+++ b/src/pardes.zig
@@ -5719,7 +5719,10 @@ pub const Pardes = struct {
     /// local socket costs microseconds and not a vsync.
     pub fn serveFs(p: *Pardes, req: ctlfs.Req) ctlfs.Reply {
         if (!ctlfs.changesPane(p, req)) return ctlfs.handle(p, req);
-        p.needs_frame = true;
+        // An address, a limit or the mark flag is nothing drawn: a script's
+        // addr write then its close costs no frame between them.
+        const drawn = if (ctlfs.Node.target(req.node)) |t| !(t == .pane and (t.pane.file == .addr or t.pane.file == .limit or t.pane.file == .mark)) else true;
+        if (drawn) p.needs_frame = true;
         p.raw_hover_intent = false;
         look.cancelLookHover(p);
         p.fs.serving = true;