patch 8.2.3149: some plugins have a problem with the error checkv8.2.3149

Problem:    Some plugins have a problem with the error check for using
            :command with -complete but without -nargs.
Solution:   In legacy script only give a warning message.

1 files changed, 20 insertions, 1 deletions

diff --git a/src/message.c b/src/message.c
index cb713d7210..7fb7264bd8 100644
--- a/src/message.c
+++ b/src/message.c
@@ -3614,6 +3614,12 @@ verbose_open(void)
     void
 give_warning(char_u *message, int hl)
 {
+    give_warning_with_source(message, hl, FALSE);
+}
+
+    void
+give_warning_with_source(char_u *message, int hl, int with_source)
+{
     // Don't do this for ":silent".
     if (msg_silent != 0)
 	return;
@@ -3629,8 +3635,21 @@ give_warning(char_u *message, int hl)
 	keep_msg_attr = HL_ATTR(HLF_W);
     else
 	keep_msg_attr = 0;
-    if (msg_attr((char *)message, keep_msg_attr) && msg_scrolled == 0)
+
+    if (with_source)
+    {
+	// Do what msg() does, but with a column offset if the warning should
+	// be after the mode message.
+	msg_start();
+	msg_source(HL_ATTR(HLF_W));
+	msg_puts(" ");
+	msg_puts_attr((char *)message, HL_ATTR(HLF_W) | MSG_HIST);
+	msg_clr_eos();
+	(void)msg_end();
+    }
+    else if (msg_attr((char *)message, keep_msg_attr) && msg_scrolled == 0)
 	set_keep_msg(message, keep_msg_attr);
+
     msg_didout = FALSE;	    // overwrite this message
     msg_nowait = TRUE;	    // don't wait for this message
     msg_col = 0;