File missing-call-to-setgroups-before-setuid.patch of Package sslh

Index: sslh-v1.16/common.c
===================================================================
--- sslh-v1.16.orig/common.c
+++ sslh-v1.16/common.c
@@ -577,6 +577,14 @@ void drop_privileges(const char* user_na
 
     set_keepcaps(1);
 
+    /* When dropping privileges from root, the `setgroups` call will
+    * remove any extraneous groups. If we don't call this, then
+    * even though our uid has dropped, we may still have groups
+    * that enable us to do super-user things. This will fail if we
+    * aren't root, so don't bother checking the return value, this
+    * is just done as an optimistic privilege dropping function.
+    */
+	setgroups(0, NULL);
     res = setgid(pw->pw_gid);
     CHECK_RES_DIE(res, "setgid");
     res = setuid(pw->pw_uid);