swaylock: Submit password on Ctrl-D

Ctrl-D functions as EOF in most cases on the terminal. login(1) & many other
programs check the password on EOF, same as Enter. To make behavior consistent,
have swaylock submit the password on Ctrl-D.

This commit moves the handling for Enter into its own static function, which is
now also called on Ctrl-D.

swaylock/password.c

@@ -77,13 +77,9 @@ static void handle_preverify_timeout(void *data) {
 	state->verify_password_timer = NULL;
 }
 
-void swaylock_handle_key(struct swaylock_state *state,
-		xkb_keysym_t keysym, uint32_t codepoint) {
-	switch (keysym) {
-	case XKB_KEY_KP_Enter: /* fallthrough */
-	case XKB_KEY_Return:
+static void submit_password(struct swaylock_state *state) {
 	if (state->args.ignore_empty && state->password.len == 0) {
-			break;
+		return;
 	}
 
 	state->auth_state = AUTH_STATE_VALIDATING;
@@ -118,11 +114,19 @@ void swaylock_handle_key(struct swaylock_state *state,
 
 	if (attempt_password(&state->password)) {
 		state->run_display = false;
-			break;
+		return;
 	}
 	state->auth_state = AUTH_STATE_INVALID;
 	damage_state(state);
 	schedule_indicator_clear(state);
+}
+
+void swaylock_handle_key(struct swaylock_state *state,
+		xkb_keysym_t keysym, uint32_t codepoint) {
+	switch (keysym) {
+	case XKB_KEY_KP_Enter: /* fallthrough */
+	case XKB_KEY_Return:
+		submit_password(state);
 		break;
 	case XKB_KEY_Delete:
 	case XKB_KEY_BackSpace:
@@ -165,6 +169,12 @@ void swaylock_handle_key(struct swaylock_state *state,
 		schedule_indicator_clear(state);
 		schedule_password_clear(state);
 		break;
+	case XKB_KEY_d:
+		if (state->xkb.control) {
+			submit_password(state);
+			break;
+		}
+		// fallthrough
 	case XKB_KEY_c: /* fallthrough */
 	case XKB_KEY_u:
 		if (state->xkb.control) {