One rule for failing builtins: the write fails, one err, no msg

A builtin that failed through a ctl failed the write and logged its err,
but through look, exec, tagexec or a column's exec it only said so on the
message row, logged as a msg, and the write succeeded. Now every click
write runs its builtin as a ctl line does (ctl.captured): a failure fails
the write, with its words (EINVAL for malformed input, else EIO or what
the words name), logs one err and no msg or announcement. get's Modified
and a look miss are shown but logged once, as their err. A control
character's refusal names its reason, a failed click reads back nothing,
and look never reads back a pane closed since. The special case for a
cut-short Edit through exec goes (the rule covers it); fs.md's table of
exceptions becomes the one rule, as does the skill.

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 ebe3279a..7745ee5e 100644
--- a/src/ninep/cols.zig
+++ b/src/ninep/cols.zig
@@ -164,7 +164,7 @@ pub fn writeExec(p: *Pardes, req: Req, serial: ?u32) Reply {
     while (lines.next()) |raw| {
         const line = std.mem.trim(u8, raw, " \t\r");
         if (line.len == 0) continue;
-        for (line) |c| if (c < ' ' and c != '\t') return Reply.fail(req.tag, E.INVAL);
+        for (line) |c| if (c < ' ' and c != '\t') return tree.failText(req.tag, E.INVAL, pardes.ctlfs.ctl.e_control);
         if (pardes.ctlfs.ctl.tooLong(req, line)) |refusal| return refusal;
         const col = if (serial) |s| layout.columnBySerial(p, s) orelse return Reply.fail(req.tag, E.NOENT) else null;
         if (p.panes[p.active] == null) return Reply.fail(req.tag, E.NOENT);
@@ -172,7 +172,7 @@ pub fn writeExec(p: *Pardes, req: Req, serial: ?u32) Reply {
         defer p.exec_column = null;
         p.exec_header = true;
         defer p.exec_header = false;
-        pardes.ctlfs.ctl.run(p, p.active, true, line, true);
+        if (pardes.ctlfs.ctl.captured(p, req, p.active, true, line, true)) |refusal| return refusal;
     }
     return .{ .tag = req.tag, .written = @intCast(req.data.len) };
 }