1 files changed, 11 insertions, 4 deletions
diff --git a/src/ninep/ctl.zig b/src/ninep/ctl.zig
index 58fcdf3a..0b1ec194 100644
--- a/src/ninep/ctl.zig
+++ b/src/ninep/ctl.zig
@@ -170,7 +170,9 @@ pub fn completeEnd(p: *Pardes, data: []const u8) usize {
 /// A null `serial` clicks at whichever pane is active as each line runs,
 /// which is what the root's own look and exec mean; a serial stays put.
 pub fn command(p: *Pardes, req: Req, serial: ?u32, exec: bool, in_tag: bool) Reply {
-    p.fs.ran_at = 0;
+    // The root's lines run at the keyboard's pane: a refusal before any runs
+    // is that pane's too, in its err record.
+    p.fs.ran_at = if (serial == null) (if (p.panes[p.active]) |pane| pane.serial else 0) else 0;
     for ([2]bool{ false, true }) |apply| {
         if (apply) p.fs.results_len = 0;
         var it = Messages.init(p, req.data);
@@ -196,7 +198,9 @@ pub fn command(p: *Pardes, req: Req, serial: ?u32, exec: bool, in_tag: bool) Rep
     return .{ .tag = req.tag, .written = @intCast(req.data.len) };
 }
 
-pub const e_too_long = std.fmt.comptimePrint("a command line is at most {d} bytes", .{pardes.exec.command_max});
+// "invalid" is the word 9ns reads as EINVAL (enameToErrno): through a
+// mount the refusal is EINVAL, as the reply's errno is.
+pub const e_too_long = std.fmt.comptimePrint("invalid command line: a command line is at most {d} bytes", .{pardes.exec.command_max});
 
 /// A line an exec would run as a command, over the most a command line may
 /// be: refused whole, before anything runs, rather than said on the message
@@ -210,7 +214,7 @@ pub fn tooLong(req: Req, line: []const u8) ?Reply {
     return tree.failText(req.tag, E.INVAL, e_too_long);
 }
 
-pub const e_control = "a command line holds no control character but a tab";
+pub const e_control = "invalid command line: it holds a control character other than a tab";
 
 /// Runs one click (`run`) as a 9P write's: a builtin that fails there fails
 /// the write, with its words and an err record, and no msg, as a ctl line
@@ -1682,7 +1686,10 @@ test "an exec line over the command limit fails the write and says the limit; a
     const refused = wr(p, root_exec, long);
     try testing.expectEqual(E.INVAL, refused.errno());
     try testing.expectEqualStrings(e_too_long, refused.reply.ename);
-    try testing.expect(th.logHas(p, "a command line is at most 1024 bytes"));
+    var rec: [96]u8 = undefined;
+    try testing.expect(th.logHas(p, try std.fmt.bufPrint(&rec, "err {d} exec: invalid command line: a command line is at most 1024 bytes", .{serialOf(p)})));
+    try testing.expectEqualStrings(e_control, wr(p, root_exec, "echo a\x01b\n").reply.ename);
+    try testing.expect(th.logHas(p, try std.fmt.bufPrint(&rec, "err {d} exec: invalid command line: it holds", .{serialOf(p)})));
     try testing.expectEqual(Status.ok, wr(p, root_exec, "Msg " ++ "z" ** 1100 ++ "\n").reply.status);
 }