[PATCH v2] common/command.c: Avoid NULL pointer use in cmd_auto_complete

[Adam Lackorzynski]

Avoid using ps_prompt having a NULL pointer. For that, use the same
approach as in uboot_cli_readline().

Suggested-by: Simon Glass <sjg at chromium.org>
Signed-off-by: Adam Lackorzynski <adam at l4re.org>
---
 common/command.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/common/command.c b/common/command.c
index 0f9dd06d72b..eb2c2123534 100644
--- a/common/command.c
+++ b/common/command.c
@@ -367,11 +367,15 @@ int cmd_auto_complete(const char *const prompt, char *buf, int *np, int *colp)
 	int i, j, k, len, seplen, argc;
 	int cnt;
 	char last_char;
-#ifdef CONFIG_CMDLINE_PS_SUPPORT
-	const char *ps_prompt = env_get("PS1");
-#else
-	const char *ps_prompt = CONFIG_SYS_PROMPT;
-#endif
+	const char *ps_prompt;
+
+	if (IS_ENABLED(CONFIG_CMDLINE_PS_SUPPORT)) {
+		ps_prompt = env_get("PS1");
+
+		if (!ps_prompt)
+			ps_prompt = CONFIG_SYS_PROMPT;
+	} else
+		ps_prompt = CONFIG_SYS_PROMPT;
 
 	if (strcmp(prompt, ps_prompt) != 0)
 		return 0;	/* not in normal console */
-- 
2.53.0