commit 14ad611ca435d97e8fd0d9ab03ddc982843298ac
author Bram Moolenaar <Bram@vim.org> Mon Feb 01 21:47:13 2016 +0100
committer Bram Moolenaar <Bram@vim.org> Mon Feb 01 21:47:13 2016 +0100
tree 512d647ad0f0d4a1ce179f28236c89bfd0b0579d
parent 1357caf31f3e447d99baf8dd6a3243e2ab38567f

patch 7.4.1233
Problem:    Channel command may cause a crash.
Solution:   Check for NULL argument. (Damien)

src/channel.c

diff --git a/src/channel.c b/src/channel.c
index f329250..8cb9a35 100644
--- a/src/channel.c
+++ b/src/channel.c
@@ -629,6 +629,8 @@
 	return;
     }
     arg = arg2->vval.v_string;
+    if (arg == NULL)
+	arg = (char_u *)"";
 
     if (STRCMP(cmd, "ex") == 0)
     {
@@ -647,7 +649,7 @@
     {
 	exarg_T ea;
 
-	ea.forceit = arg != NULL && *arg != NUL;
+	ea.forceit = *arg != NUL;
 	ex_redraw(&ea);
 	showruler(FALSE);
 	setcursor();