A 9P request that fills a stillborn scratch's column replaces the scratch before it is answered

A pane that joins a column holding only an empty +New takes the column, but
that replacement ran at the end of the editor's next update, not of a 9P
request: a look answered 19 while index still listed the +New 18, whose del
came later. serveFs, a step of its own, now runs it too before answering.

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

1 files changed, 4 insertions, 0 deletions

diff --git a/src/pardes.zig b/src/pardes.zig
index 43d8e94d..12de47fa 100644
--- a/src/pardes.zig
+++ b/src/pardes.zig
@@ -4999,6 +4999,10 @@ pub const Pardes = struct {
         look.cancelLookHover(p);
         const reply = ctlfs.handle(p, req);
         if (reply.status == .err and (req.op == .write or req.op == .setattr)) ctlfs.events.noteError(p, req, reply);
+        // A pane that joined a column holding only a stillborn scratch takes
+        // it now, before the answer: one read of index after the look shows
+        // the replacement done, and the log has its del with the new.
+        exec.replaceStillborn(p);
         // The request was a whole step of its own, so it settles the way a
         // step does: the cursor and scroll reconciled, the scripted panes
         // told, and the panes it made announced to /log now rather than at