Try to fix DRM lease code

src/instance.c

@@ -193,19 +193,26 @@ static int drm_find_psvr_xcb(Instance * instance)
 		return(0);
 	}
 
+	const xcb_setup_t *setup = xcb_get_setup(instance->connection);
+
+	int screen = instance->screen;
+
+	xcb_window_t root = 0;
+
 	xcb_screen_iterator_t s_i;
 
 	int i_s = 0;
 
-	for (s_i = xcb_setup_roots_iterator(xcb_get_setup(instance->connection)); s_i.rem; xcb_screen_next(&s_i), i_s++)
+	for (s_i = xcb_setup_roots_iterator(setup); s_i.rem; xcb_screen_next(&s_i), i_s++)
 	{
 		printf ("index %d screen %d\n", s_i.index, instance->screen);
-		if (i_s == instance->screen)
+		if (screen == 0) {
-				break;
+			root = s_i.data->root;
+			break;
+		}
+		--screen;
 	}
 
-	xcb_window_t root = s_i.data->root;
-
 	printf("root %x\n", root);
 
 	xcb_randr_get_screen_resources_cookie_t gsr_c = xcb_randr_get_screen_resources(instance->connection, root);
@@ -218,44 +225,90 @@ static int drm_find_psvr_xcb(Instance * instance)
 		return(0);
 	}
 
+	xcb_timestamp_t config_timestamp = gsr_r->config_timestamp;
+
 	xcb_randr_output_t *ro = xcb_randr_get_screen_resources_outputs(gsr_r);
 	int o, c;
 
+	int			num_outputs = gsr_r->num_outputs;
+
 	xcb_randr_output_t output = 0;
 
+	char * output_name = NULL;
+
 	/* Find a connected but idle output */
-	for (o = 0; output == 0 && o < gsr_r->num_outputs; o++) {
+	for (o = 0; o < num_outputs; o++) {
-			xcb_randr_get_output_info_cookie_t goi_c = xcb_randr_get_output_info(instance->connection, ro[o], gsr_r->config_timestamp);
+			xcb_randr_get_output_info_cookie_t goi_c = xcb_randr_get_output_info(instance->connection, ro[o], config_timestamp);
 
 			xcb_randr_get_output_info_reply_t *goi_r = xcb_randr_get_output_info_reply(instance->connection, goi_c, NULL);
 
+			output_name = xcb_randr_get_output_info_name(goi_r);
+
 			/* Find the first connected but unused output */
 			if (goi_r->connection == XCB_RANDR_CONNECTION_CONNECTED &&
 				goi_r->crtc == 0) {
 					output = ro[o];
+					break;
 			}
 
 			free(goi_r);
 	}
 
+	if (!output)
+	{
+		fprintf(stderr, "no free output found\n");
+		return 0;
+	}
+
 	xcb_randr_crtc_t *rc = xcb_randr_get_screen_resources_crtcs(gsr_r);
 
 	xcb_randr_crtc_t crtc = 0;
 
-	/* Find an idle crtc */
+	xcb_randr_crtc_t    idle_crtc = XCB_NONE;
+	xcb_randr_crtc_t    active_crtc = XCB_NONE;
+
+	/* Find either a crtc already connected to the desired output or idle */
 	for (c = 0; crtc == 0 && c < gsr_r->num_crtcs; c++) {
 			xcb_randr_get_crtc_info_cookie_t gci_c = xcb_randr_get_crtc_info(instance->connection, rc[c], gsr_r->config_timestamp);
 
 			xcb_randr_get_crtc_info_reply_t *gci_r = xcb_randr_get_crtc_info_reply(instance->connection, gci_c, NULL);
 
 			/* Find the first connected but unused crtc */
-			if (gci_r->mode == 0)
+
-					crtc = rc[c];
+			if (gci_r->mode) {
+				int num_outputs = xcb_randr_get_crtc_info_outputs_length(gci_r);
+				xcb_randr_output_t *outputs = xcb_randr_get_crtc_info_outputs(gci_r);
+				for (int o = 0; o < num_outputs; o++)
+					if (outputs[o] == output && num_outputs == 1) {
+						active_crtc = rc[c];
+						break;
+					}
+
+			} else if (idle_crtc == 0) {
+				int num_possible = xcb_randr_get_crtc_info_possible_length(gci_r);
+				xcb_randr_output_t *possible = xcb_randr_get_crtc_info_possible(gci_r);
+				for (int p = 0; p < num_possible; p++)
+					if (possible[p] == output) {
+						idle_crtc = rc[c];
+						break;
+					}
+			}
 
 			free(gci_r);
 	}
 
-	free(gsr_r);
+	if (active_crtc)
+		crtc = active_crtc;
+	else
+		crtc = idle_crtc;
+
+//	free(gsr_r);
+
+	if (crtc == XCB_NONE)
+	{
+		fprintf(stderr, "cannot find usable CRTC\n");
+		return 0;
+	}
 
 	printf("output %x crtc %x\n", output, crtc);
 
@@ -270,9 +323,10 @@ static int drm_find_psvr_xcb(Instance * instance)
 																   &output);
 	xcb_randr_create_lease_reply_t *rcl_r = xcb_randr_create_lease_reply(instance->connection, rcl_c, NULL);
 
-	if (!rcl_r) {
+	if (!rcl_r)
-			printf("create_lease failed\n");
+	{
-			exit(1);
+		fprintf(stderr, "create_lease failed\n");
+		return 0;
 	}
 
 	int *rcl_f = xcb_randr_create_lease_reply_fds(instance->connection, rcl_r);
@@ -299,7 +353,7 @@ bool InitInstance(Instance * instance)
 	}
 	else
 	{
-		fprintf(stderr, "couldn't find devicee\n");
+		fprintf(stderr, "couldn't find device\n");
 		return false;
 	}