swaylock: Handle possible fail on password realloc

swaylock/main.c

@@ -113,6 +113,8 @@ bool verify_password() {
 
 void notify_key(enum wl_keyboard_key_state state, xkb_keysym_t sym, uint32_t code, uint32_t codepoint) {
 	int redraw_screen = 0;
+	char *password_realloc;
+
 	if (state == WL_KEYBOARD_KEY_STATE_PRESSED) {
 		switch (sym) {
 		case XKB_KEY_Return:
@@ -129,6 +131,7 @@ void notify_key(enum wl_keyboard_key_state state, xkb_keysym_t sym, uint32_t cod
 			redraw_screen = 1;
 
 			password_size = 1024;
+			free(password);
 			password = malloc(password_size);
 			password[0] = '\0';
 			break;
@@ -149,7 +152,17 @@ void notify_key(enum wl_keyboard_key_state state, xkb_keysym_t sym, uint32_t cod
 				int i = strlen(password);
 				if (i + 1 == password_size) {
 					password_size += 1024;
-					password = realloc(password, password_size);
+					password_realloc = realloc(password, password_size);
+					// reset password if realloc fails.
+					if (password_realloc == NULL) {
+						password_size = 1024;
+						free(password);
+						password = malloc(password_size);
+						password[0] = '\0';
+						break;
+					} else {
+						password = password_realloc;
+					}
 				}
 				password[i] = (char)codepoint;
 				password[i + 1] = '\0';
@@ -305,7 +318,7 @@ int main(int argc, char **argv) {
 			break;
 		}
 		switch (c) {
-		case 'c': 
+		case 'c':
 		{
 			int colorlen = strlen(optarg);
 			if (colorlen < 6 || colorlen == 7 || colorlen > 8) {