overload: Allow nested swap actions (#395)

src/keyboard.c

@@ -582,6 +582,13 @@ static long process_descriptor(struct keyboard *kbd, uint8_t code,
 
 		if (pressed) {
 			kbd->overload_start_time = time;
+
+			/*
+			 * Preserve the original last layer activation code in the event
+			 * that the tap action is a swap.
+			 */
+			kbd->overload_last_layer_code = kbd->last_layer_code;
+
 			activate_layer(kbd, code, idx);
 			update_mods(kbd, -1, 0);
 		} else {
@@ -591,6 +598,7 @@ static long process_descriptor(struct keyboard *kbd, uint8_t code,
 			if (kbd->last_pressed_code == code &&
 			    (!kbd->config.overload_tap_timeout ||
 			     ((time - kbd->overload_start_time) < kbd->config.overload_tap_timeout))) {
+				kbd->last_layer_code = kbd->overload_last_layer_code;
 				clear_oneshot(kbd);
 
 				process_descriptor(kbd, code, action, dl, 1, time);

src/keyboard.h

@@ -48,6 +48,8 @@ struct keyboard {
 
 	struct macro *active_macro;
 	int active_macro_layer;
+	int overload_last_layer_code;
+
 	long macro_timeout;
 	long oneshot_timeout;
 

t/overload-swap.t

@@ -0,0 +1,27 @@
+6 down
+x down
+x up
+a down
+a up
+6 up
+6 down
+x down
+a down
+a up
+x up
+6 up
+
+control down
+meta down
+meta up
+shift down
+control up
+a down
+a up
+shift up
+control down
+meta down
+a down
+a up
+meta up
+control up

t/test.conf

@@ -67,6 +67,7 @@ m = macro(mac)
 e = macro(leftcontrol o+n leftcontrol+1)
 b = macro(leftcontrol+n)
 c = macro(leftcontrol n)
+x = overload(meta, swap(shift))
 
 [test]