Check return value of get_screen.

diff --git a/spectrwm.c b/spectrwm.c
index ace7c52793e4a161bc27457348861a699e0b1211..17e29121ba58934b0580464cbb7f30df68a65b27 100644 (file)
--- a/spectrwm.c
+++ b/spectrwm.c
@@ -758,12 +758,12 @@ parse_rgb(const char *rgb, uint16_t *rr, uint16_t *gg, uint16_t *bb)
 xcb_screen_t *
 get_screen(int screen)
 {
-       xcb_screen_iterator_t i;
+       xcb_screen_iterator_t   iter;
 
-       i = xcb_setup_roots_iterator(xcb_get_setup(conn));
-       for (; i.rem; --screen, xcb_screen_next(&i))
+       iter = xcb_setup_roots_iterator(xcb_get_setup(conn));
+       for (; iter.rem; --screen, xcb_screen_next(&iter))
                if (screen == 0)
-                       return (i.data);
+                       return (iter.data);
 
        return (NULL);
 }
@@ -1347,7 +1347,9 @@ custom_region(char *val)
                    sidx, num_screens);
        sidx--;
 
-       screen = get_screen(sidx);
+       if ((screen = get_screen(sidx)) == NULL)
+               errx(1, "ERROR: can't get screen %d.", sidx);
+
        if (w < 1 || h < 1)
                errx(1, "region %ux%u+%u+%u too small", w, h, x, y);
 
@@ -1901,10 +1903,13 @@ bar_setup(struct swm_region *r)
 {
        char                    *font, *fontpos, *dup, *search;
        int                     count;
-       xcb_screen_t            *screen = get_screen(r->s->idx);
+       xcb_screen_t            *screen;
        uint32_t                wa[3];
        XRenderColor            color;
 
+       if ((screen = get_screen(r->s->idx)) == NULL)
+               errx(1, "ERROR: can't get screen %d.", r->s->idx);
+
        if (r->bar != NULL)
                return;
 
@@ -7406,7 +7411,8 @@ enable_wm(void)
        /* this causes an error if some other window manager is running */
        num_screens = xcb_setup_roots_length(xcb_get_setup(conn));
        for (i = 0; i < num_screens; i++) {
-               sc = get_screen(i);
+               if ((sc = get_screen(i)) == NULL)
+                       errx(1, "ERROR: can't get screen %d.", i);
                DNPRINTF(SWM_D_INIT, "enable_wm: screen %d, root: 0x%x\n",
                    i, sc->root);
                wac = xcb_change_window_attributes_checked(conn, sc->root,
@@ -7511,7 +7517,10 @@ scan_xrandr(int i)
        xcb_randr_get_crtc_info_cookie_t                cic;
        xcb_randr_get_crtc_info_reply_t                 *cir = NULL;
        xcb_randr_crtc_t                                *crtc;
-       xcb_screen_t                                    *screen = get_screen(i);
+       xcb_screen_t                                    *screen;
+
+       if ((screen = get_screen(i)) == NULL)
+               errx(1, "ERROR: can't get screen %d.", i);
 
        num_screens = xcb_setup_roots_length(xcb_get_setup(conn));
        if (i >= num_screens)
@@ -7679,6 +7688,7 @@ setup_screens(void)
        struct workspace        *ws;
        uint32_t                gcv[1], wa[1];
        const xcb_query_extension_reply_t *qep;
+       xcb_screen_t                            *screen;
        xcb_cursor_t                            cursor;
        xcb_font_t                              cursor_font;
        xcb_randr_query_version_cookie_t        c;
@@ -7719,7 +7729,9 @@ setup_screens(void)
                screens[i].idx = i;
                TAILQ_INIT(&screens[i].rl);
                TAILQ_INIT(&screens[i].orl);
-               screens[i].root = get_screen(i)->root;
+               if ((screen = get_screen(i)) == NULL)
+                       errx(1, "ERROR: can't get screen %d.", i);
+               screens[i].root = screen->root;
 
                /* set default colors */
                setscreencolor("red", i + 1, SWM_S_COLOR_FOCUS);