Empty lines in output of "exec" command cause "Not enough parameters given" errors

[irssibot]

• • • Issue #902 opened by @dj1yfk

If a command is run by the exec function with output to the channel (i. e. /exec -o), empty lines in the process output will cause an error ("Not enough parameters given") because the "command msg" signal expects three parameters but only receives two.

In normal chat mode, an empty line is caught and ignored in the function "event_text":

irssi-0.8.16-rc1/src/fe-common/core/chat-completion.c (1065ff)
    if (*data == '\0') {
        /* empty line, forget it. */
                signal_stop();
        return;
    }

For exec, there's no test for the length of the string (function sig_exec_input). In some cases (no -o option used) empty lines are OK, but when the output is sent to the channel, it will fail.

It is not completely obvious to me what the correct behaviour should be. Possible options:

• Ignore empty lines (like above, but it would have to be done within if (rec->target != NULL) { } to make sure it doesn't remove blank lines from local output).
• Send a line with just a space character instead of the empty line.

The latter would probably give the "expected" behaviour (at least visually).

Diff of proposed patch attached.

[irssibot]

• • • Attachment 299 by @dj1yfk

irssi-0.8.16-rc1-exec.patch

--- irssi-0.8.16-rc1.orig/src/fe-common/core/fe-exec.c  2013-06-25 23:50:41.000000000 +0200
+++ irssi-0.8.16-rc1/src/fe-common/core/fe-exec.c   2013-09-19 23:38:52.000000000 +0200
@@ -615,7 +615,7 @@

        str = g_strconcat(rec->target_nick ? "-nick " :
                  rec->target_channel ? "-channel " : "",
-                 rec->target, " ", text, NULL);
+                 rec->target, " ", *text ? text : " ", NULL);
        signal_emit(rec->notice ? "command notice" : "command msg",
                3, str, server, item);
                 g_free(str);