[git commit] ash: fix command -- crash

[Denys Vlasenko]

commit: http://git.busybox.net/busybox/commit/?id=e2f32c02b149f5a128c634231a0ef12d03843967
branch: http://git.busybox.net/busybox/commit/?id=refs/heads/master

busybox sh -c 'command --' segfaults because parse_command_args
returns a pointer to a null pointer.

Based on commit 18071c7 from git://git.kernel.org/pub/scm/utils/dash/dash.git
by Gerrit Pape.

Signed-off-by: Denys Vlasenko <vda.linux at googlemail.com>
---
 shell/ash.c |    7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/shell/ash.c b/shell/ash.c
index 18c7ff5..8f0a5e0 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -8878,14 +8878,15 @@ parse_command_args(char **argv, const char **path)
 	for (;;) {
 		cp = *++argv;
 		if (!cp)
-			return 0;
+			return NULL;
 		if (*cp++ != '-')
 			break;
 		c = *cp++;
 		if (!c)
 			break;
 		if (c == '-' && !*cp) {
-			argv++;
+			if (!*++argv)
+				return NULL;
 			break;
 		}
 		do {
@@ -8895,7 +8896,7 @@ parse_command_args(char **argv, const char **path)
 				break;
 			default:
 				/* run 'typecmd' for other options */
-				return 0;
+				return NULL;
 			}
 			c = *cp++;
 		} while (c);