Protect prompt completion memcpy() calls with a NULL check.

The behavior of memcpy() is undefined when dest is NULL, even if n is
0.  It's possible to trigger this, somewhat deliberately, for these
two cases, so add a guard check.

1 files changed, 4 insertions, 2 deletions

diff --git a/enter.c b/enter.c
index 1daa10b2..f09dd265 100644
--- a/enter.c
+++ b/enter.c
@@ -592,7 +592,8 @@ int _mutt_enter_string (char *buf, size_t buflen, int col,
 	    {
 	      templen = state->lastchar - i;
 	      safe_realloc (&tempbuf, templen * sizeof (wchar_t));
-	      memcpy (tempbuf, state->wbuf + i, templen * sizeof (wchar_t));
+              if (tempbuf)
+                memcpy (tempbuf, state->wbuf + i, templen * sizeof (wchar_t));
 	    }
 	    else
 	      BEEP ();
@@ -749,7 +750,8 @@ int _mutt_enter_string (char *buf, size_t buflen, int col,
 	    {
 	      templen = state->lastchar;
 	      safe_realloc (&tempbuf, templen * sizeof (wchar_t));
-	      memcpy (tempbuf, state->wbuf, templen * sizeof (wchar_t));
+              if (tempbuf)
+                memcpy (tempbuf, state->wbuf, templen * sizeof (wchar_t));
 	    }
 	    else
 	      BEEP (); /* let the user know that nothing matched */