options: fix filter list comparison (again)

This was completely broken: it compared the first item of the filter
list only. Apparently I forgot that this is a list. This probably broke
aspects of runtime filter changing probably since commit  b16cea750f.

Fix this, and remove some redundant code from obj_settings_equals().
Which is not the same as m_obj_settings_equal(), so rename it to make
confusing them harder. (obj_setting_match() has these very weird label
semantics that should probably just be killed. Or not.)

filters/f_output_chain.c

@@ -524,8 +524,7 @@ bool mp_output_chain_update_filters(struct mp_output_chain *c,
         struct mp_user_filter *u = NULL;
 
         for (int i = 0; i < p->num_user_filters; i++) {
-            struct m_option t = {.type = &m_option_type_obj_settings_list};
-            if (!used[i] && m_option_equal(&t, &entry, &p->user_filters[i]->args))
+            if (!used[i] && m_obj_settings_equal(entry, p->user_filters[i]->args))
             {
                 u = p->user_filters[i];
                 used[i] = true;

options/m_option.c

@@ -2813,27 +2813,13 @@ static void obj_setting_free(m_obj_settings_t *item)
 }
 
 // If at least one item has a label, compare labels only - otherwise ignore them.
-static bool obj_setting_equals(m_obj_settings_t *a, m_obj_settings_t *b)
+static bool obj_setting_match(m_obj_settings_t *a, m_obj_settings_t *b)
 {
     bstr la = bstr0(a->label), lb = bstr0(b->label);
     if (la.len || lb.len)
         return bstr_equals(la, lb);
-    if (strcmp(a->name, b->name) != 0)
-        return false;
 
-    int a_attr_count = 0;
-    while (a->attribs && a->attribs[a_attr_count])
-        a_attr_count++;
-    int b_attr_count = 0;
-    while (b->attribs && b->attribs[b_attr_count])
-        b_attr_count++;
-    if (a_attr_count != b_attr_count)
-        return false;
-    for (int n = 0; n < a_attr_count; n++) {
-        if (strcmp(a->attribs[n], b->attribs[n]) != 0)
-            return false;
-    }
-    return true;
+    return m_obj_settings_equal(a, b);
 }
 
 static int obj_settings_list_num_items(m_obj_settings_t *obj_list)
@@ -2898,7 +2884,7 @@ static int obj_settings_find_by_content(m_obj_settings_t *obj_list,
                                         m_obj_settings_t *item)
 {
     for (int n = 0; obj_list && obj_list[n].name; n++) {
-        if (obj_setting_equals(&obj_list[n], item))
+        if (obj_setting_match(&obj_list[n], item))
             return n;
     }
     return -1;
@@ -3632,6 +3618,18 @@ static bool obj_settings_list_equal(const m_option_t *opt, void *pa, void *pb)
     if (a == b || !a || !b)
         return a == b;
 
+    for (int n = 0; a[n].name || b[n].name; n++) {
+        if (!a[n].name || !b[n].name)
+            return false;
+        if (!m_obj_settings_equal(&a[n], &b[n]))
+            return false;
+    }
+
+    return true;
+}
+
+bool m_obj_settings_equal(struct m_obj_settings *a, struct m_obj_settings *b)
+{
     if (!str_equal(NULL, &a->name, &b->name))
         return false;
 

options/m_option.h

@@ -181,6 +181,8 @@ typedef struct m_obj_settings {
     char **attribs;
 } m_obj_settings_t;
 
+bool m_obj_settings_equal(struct m_obj_settings *a, struct m_obj_settings *b);
+
 struct m_opt_choice_alternatives {
     char *name;
     int value;