A ctl or exec line with no newline runs with its write and fails it, unless it needs more

A last line with no newline was held to the close, so printf bogus > ctl answered 0 and failed only in the log, Edit ,s/zzz/y/ too. A write shorter than its Twrite is the whole of what was written (acme takes each write whole): its tail runs then and a failure is the write's. It is held only when the parser says it needs more -- an open { block, an a/c/i text -- or when the write filled its Twrite and may go on (the listener tells the core the room, msize less its header).

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

1 files changed, 2 insertions, 0 deletions

diff --git a/src/9p_io.zig b/src/9p_io.zig
index 91240b57..7f490f81 100644
--- a/src/9p_io.zig
+++ b/src/9p_io.zig
@@ -261,6 +261,7 @@ pub const Listener = struct {
             return conn.reply(&later, "");
         }
         const core = l.core;
+        core.fs.write_room = if (conn.engine.protocol.msize > 24) conn.engine.protocol.msize - 24 else 0;
         const epoch = pardes.turn.epoch;
         const restores = pardes.turn.restores;
         // Asked first: a release that runs a held line has none after.
@@ -506,6 +507,7 @@ pub const Listener = struct {
 
     /// Answers one QUIC request, on the editor's thread.
     fn step(l: *Listener, srv: *Srv, req: pardes.ctlfs.Req) void {
+        l.core.fs.write_room = if (srv.protocol.msize > 24) srv.protocol.msize - 24 else 0;
         const reply = l.core.serveFs(req);
         srv.reply(&reply, l.core.fsPayload(reply));
         if (req.op == .release) l.collectOs();