ucm: handle empty string also for ${env:} substitution

Signed-off-by: Jaroslav Kysela <perex@perex.cz>

diff --git a/src/ucm/ucm_subs.c b/src/ucm/ucm_subs.c
index 2261bdc20f3d2ba9e0ae65dbd200458ca3b03752..e62290ea0592e25f9794a312c7c4f123791d7267 100644 (file)
--- a/src/ucm/ucm_subs.c
+++ b/src/ucm/ucm_subs.c
@@ -490,7 +490,13 @@ static char *rval_env(snd_use_case_mgr_t *uc_mgr ATTRIBUTE_UNUSED, const char *i
 {
        char *e;
 
-       e = getenv(id);
+       if (*id == '-') {
+               e = getenv(id + 1);
+               if (e == NULL)
+                       e = "";
+       } else {
+               e = getenv(id);
+       }
        if (e)
                return strdup(e);
        return NULL;