From 5062565e824f02c9838bd781862a9396c52d4111 Mon Sep 17 00:00:00 2001 From: Jaroslav Kysela Date: Tue, 17 May 2022 14:35:51 +0200 Subject: [PATCH] ucm: allow '-' prefix to avoid errors when the variable is not defined It may be useful to check if variable is not defined. Signed-off-by: Jaroslav Kysela --- src/ucm/ucm_subs.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/src/ucm/ucm_subs.c b/src/ucm/ucm_subs.c index 8b42b889..a7d79430 100644 --- a/src/ucm/ucm_subs.c +++ b/src/ucm/ucm_subs.c @@ -549,13 +549,20 @@ static char *rval_sysfs(snd_use_case_mgr_t *uc_mgr ATTRIBUTE_UNUSED, const char static char *rval_var(snd_use_case_mgr_t *uc_mgr, const char *id) { const char *v; + bool ignore_not_found = false; if (uc_mgr->conf_format < 3) { uc_error("variable substitution is supported in v3+ syntax"); return NULL; } + if (id[0] == '-') { + ignore_not_found = true; + id++; + } v = uc_mgr_get_variable(uc_mgr, id); + if (v == NULL && ignore_not_found) + v = ""; if (v) return strdup(v); return NULL; -- 2.47.1