Sort binding key lists

Sort the list comprising the set of keys for the binding in ascending
order. (Keyboard shortcuts depend only on the set of simultaneously
pressed keys, not their order, so this change should have no external
effect.) This simplifies comparisons between bindings.

include/sway/config.h

@@ -30,7 +30,7 @@ struct sway_binding {
 	bool release;
 	bool locked;
 	bool bindcode;
-	list_t *keys;
+	list_t *keys; // sorted in ascending order
 	uint32_t modifiers;
 	char *command;
 };

sway/commands/bind.c

@@ -32,7 +32,7 @@ void free_sway_binding(struct sway_binding *binding) {
  * Note that keyboard layout is not considered, so the bindings might actually
  * not be equivalent on some layouts.
  */
-bool binding_key_compare(struct sway_binding *binding_a,
+static bool binding_key_compare(struct sway_binding *binding_a,
 		struct sway_binding *binding_b) {
 	if (binding_a->release != binding_b->release) {
 		return false;
@@ -50,18 +50,12 @@ bool binding_key_compare(struct sway_binding *binding_a,
 		return false;
 	}
 
+	// Keys are sorted
 	int keys_len = binding_a->keys->length;
 	for (int i = 0; i < keys_len; ++i) {
-		uint32_t key_a = *(uint32_t*)binding_a->keys->items[i];
-		bool found = false;
-		for (int j = 0; j < keys_len; ++j) {
-			uint32_t key_b = *(uint32_t*)binding_b->keys->items[j];
-			if (key_b == key_a) {
-				found = true;
-				break;
-			}
-		}
-		if (!found) {
+		uint32_t key_a = *(uint32_t *)binding_a->keys->items[i];
+		uint32_t key_b = *(uint32_t *)binding_b->keys->items[i];
+		if (key_a != key_b) {
 			return false;
 		}
 	}
@@ -69,6 +63,12 @@ bool binding_key_compare(struct sway_binding *binding_a,
 	return true;
 }
 
+static int key_qsort_cmp(const void *keyp_a, const void *keyp_b) {
+	uint32_t key_a = **(uint32_t **)keyp_a;
+	uint32_t key_b = **(uint32_t **)keyp_b;
+	return (key_a < key_b) ? -1 : ((key_a > key_b) ? 1 : 0);
+}
+
 static struct cmd_results *cmd_bindsym_or_bindcode(int argc, char **argv,
 		bool bindcode) {
 	const char *bindtype = bindcode ? "bindcode" : "bindsym";
@@ -169,6 +169,9 @@ static struct cmd_results *cmd_bindsym_or_bindcode(int argc, char **argv,
 	free_flat_list(split);
 	binding->order = binding_order++;
 
+	// sort ascending
+	list_qsort(binding->keys, key_qsort_cmp);
+
 	list_t *mode_bindings;
 	if (bindcode) {
 		mode_bindings = config->current_mode->keycode_bindings;