alsa-mixer: Fix path subset detection

The old logic assumed that if path A was a subset of path B, the
element list in B would have all elements of A in the beginning of
B's list, in the same order as A. This assumption was invalid, causing
some subset cases to not get detected. We need to search through the
full element list of B every time before we can conclude that B
doesn't have the element that we're inspecting.

diff --git a/src/modules/alsa/alsa-mixer.c b/src/modules/alsa/alsa-mixer.c
index b4f4bbd83613c497acaf9ad223a8f81ee560ba32..48715234afdb73e19ad131e49ce8e3d232b6cc8f 100644 (file)
--- a/src/modules/alsa/alsa-mixer.c
+++ b/src/modules/alsa/alsa-mixer.c
@@ -3218,21 +3218,21 @@ static void path_set_condense(pa_alsa_path_set *ps, snd_mixer_t *m) {
             }
 
             /* Compare the elements of each set... */
-            ea = p->elements;
-            eb = p2->elements;
+            PA_LLIST_FOREACH(ea, p->elements) {
+                bool found_matching_element = false;
 
-            while (is_subset) {
-                if (!ea && !eb)
+                if (!is_subset)
                     break;
-                else if ((ea && !eb) || (!ea && eb))
-                    is_subset = false;
-                else if (pa_streq(ea->alsa_name, eb->alsa_name)) {
-                    if (element_is_subset(ea, eb, m)) {
-                        ea = ea->next;
-                        eb = eb->next;
-                    } else
-                        is_subset = false;
-                } else
+
+                PA_LLIST_FOREACH(eb, p2->elements) {
+                    if (pa_streq(ea->alsa_name, eb->alsa_name)) {
+                        found_matching_element = true;
+                        is_subset = element_is_subset(ea, eb, m);
+                        break;
+                    }
+                }
+
+                if (!found_matching_element)
                     is_subset = false;
             }