Fix crash on NULL class/name strings in bar. Reported by and similar diff

from Gregory Edigarov.

ok marco

diff --git a/scrotwm.c b/scrotwm.c
index 98e049070db7a35556dcb19a8ba6158f6525400f..045bc531e82951857917b57e8e72b2cdf6371936 100644 (file)
--- a/scrotwm.c
+++ b/scrotwm.c
@@ -566,7 +566,7 @@ bar_update(void)
        time_t                  tmt;
        struct tm               tm;
        struct swm_region       *r;
-       int                     i, x;
+       int                     i, x, do_class, do_name;
        size_t                  len;
        char                    s[SWM_BAR_MAX];
        char                    loc[SWM_BAR_MAX];
@@ -606,11 +606,13 @@ bar_update(void)
                status = XGetClassHint(display, cur_focus->id, xch);
                if (status == BadWindow || status == BadAlloc)
                        goto out;
-               if (title_class_enabled)
+               do_class = (title_class_enabled && xch->res_class != NULL);
+               do_name = (title_name_enabled && xch->res_name != NULL);
+               if (do_class)
                        strlcat(s, xch->res_class, sizeof s);
-               if (title_name_enabled && title_class_enabled)
+               if (do_class && do_name)
                        strlcat(s, ":", sizeof s);
-               if (title_name_enabled)
+               if (do_name)
                        strlcat(s, xch->res_name, sizeof s);
        }
 out: