A ctl refusal quotes the offending word alone, everywhere: wrong #args in control message "Newcol", not "Newcol 2"

Some refusals quoted the whole line, arguments and all ("Newcol 2",
"Verbose maybe", "lock x"), others the word alone ("Theme", "Mount"),
so a script matching one could not match the other. Every ctl
refusal, the root's, a pane's and a column's, now quotes the message's
word alone, and one too long to quote whole gives up its middle.

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

1 files changed, 2 insertions, 2 deletions

diff --git a/src/ninep/cols.zig b/src/ninep/cols.zig
index b2e62d28..e3b456ba 100644
--- a/src/ninep/cols.zig
+++ b/src/ninep/cols.zig
@@ -167,10 +167,10 @@ pub fn writeCtl(p: *Pardes, req: Req, serial: u32) Reply {
         } else false;
         // Plan 9's words for it, so a mount's errno is EINVAL as the root's
         // and a pane's ctl give (9ns reads "control message").
-        if (!takes) return tree.failText(req.tag, E.INVAL, std.fmt.bufPrint(&p.fs.ename, "unknown control message \"{s}\": a column's ctl takes Delcol, Joincol, New or Tty", .{line[0..@min(line.len, 64)]}) catch "unknown control message");
+        if (!takes) return tree.failText(req.tag, E.INVAL, std.fmt.bufPrint(&p.fs.ename, "unknown control message \"{s}\": a column's ctl takes Delcol, Joincol, New or Tty", .{pardes.ctlfs.ctl.firstWord(line)[0..@min(pardes.ctlfs.ctl.firstWord(line).len, 64)]}) catch "unknown control message");
         // Only Tty takes a word (its shell); `New extra` is no New.
         if (!std.mem.eql(u8, word, "Tty") and word.len != line.len)
-            return tree.failText(req.tag, E.INVAL, std.fmt.bufPrint(&p.fs.ename, "wrong #args in control message \"{s}\"", .{line[0..@min(line.len, 64)]}) catch "wrong #args in control message");
+            return tree.failText(req.tag, E.INVAL, std.fmt.bufPrint(&p.fs.ename, "wrong #args in control message \"{s}\"", .{pardes.ctlfs.ctl.firstWord(line)[0..@min(pardes.ctlfs.ctl.firstWord(line).len, 64)]}) catch "wrong #args in control message");
         const col = layout.columnBySerial(p, serial) orelse return Reply.fail(req.tag, E.NOENT);
         p.exec_column = col;
         defer p.exec_column = null;