[PATCH v3 1/1] input: avoid NULL dereference

[Heinrich Schuchardt]

Before using the result of env_get("stdin") we must check if it is NULL.

Avoid #if. This resolves the -Wunused-but-set-variable issue and we don't
need a dummy assignment in the else branch. Anyway this warning is
disabled in the Makefile.

For sake of readability use an early return after the configuration check.

Checking CONFIG_SPL_BUILD is incorrect as env_get() is only defined if
CONFIG_$(SPL_TPL)ENV_SUPPORT=y.

Fixes: 985ca3945fa3 ("spl: input: Allow input in SPL and TPL")
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt at canonical.com>
---
v2:
	avoid #if

v3:
	use an early return after configuration check
	remove CONFIG_SPL_BUILD check
---
 drivers/input/input.c | 25 +++++++++++++++----------
 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/drivers/input/input.c b/drivers/input/input.c
index a4341e8c7c..743ba89f77 100644
--- a/drivers/input/input.c
+++ b/drivers/input/input.c
@@ -669,17 +669,22 @@ int input_stdio_register(struct stdio_dev *dev)
 	int error;
 
 	error = stdio_register(dev);
-#if !defined(CONFIG_SPL_BUILD) || CONFIG_IS_ENABLED(ENV_SUPPORT)
-	/* check if this is the standard input device */
-	if (!error && strcmp(env_get("stdin"), dev->name) == 0) {
-		/* reassign the console */
-		if (OVERWRITE_CONSOLE ||
-				console_assign(stdin, dev->name))
-			return -1;
+
+	if (!CONFIG_IS_ENABLED(ENV_SUPPORT))
+		return 0;
+
+	if (!error) {
+		const char *cstdin;
+
+		/* check if this is the standard input device */
+		cstdin = env_get("stdin");
+		if (cstdin && !strcmp(cstdin, dev->name)) {
+			/* reassign the console */
+			if (OVERWRITE_CONSOLE ||
+			    console_assign(stdin, dev->name))
+				return -1;
+		}
 	}
-#else
-	error = error;
-#endif
 
 	return 0;
 }
-- 
2.40.1