v1:
As long as VERSION in /etc/os-release has been commented out for rolling
release, we can replace openSUSE Tumbleweed specific handling for grub
distributor with a generic one.

v2:
Use /usr/lib/os-release as fallback to /etc/os-release

Index: grub-2.06/grub-core/osdep/unix/config.c
===================================================================
--- grub-2.06.orig/grub-core/osdep/unix/config.c
+++ grub-2.06/grub-core/osdep/unix/config.c
@@ -61,6 +61,131 @@ grub_util_get_localedir (void)
   return LOCALEDIR;
 }
 
+#ifdef __linux__
+static char *
+os_release_get_val (const char *buf, const char *key)
+{
+  const char *ptr = buf;
+  char *ret;
+
+  while (*ptr && grub_isspace(*ptr))
+    ptr++;
+
+  if (*ptr == '#')
+    return NULL;
+
+  if (grub_strncmp (ptr, key, grub_strlen (key)) != 0)
+    return NULL;
+
+  ptr += grub_strlen (key);
+  if (*ptr++ != '=' || *ptr == '\0')
+    return NULL;
+
+  if (*ptr == '"' || *ptr == '\'')
+    {
+      char c = *ptr;
+      int i = 0;
+      char *tmp, *ptmp;
+
+      if (*++ptr == '\0')
+	return NULL;
+
+      tmp = grub_strdup (ptr);
+      if ((ptmp = grub_strrchr (tmp, c)))
+	*ptmp = '\0';
+
+      ret = malloc (grub_strlen (tmp) + 1);
+      ptmp = tmp;
+      while (*ptmp)
+	{
+	  if (*ptmp != '\\' || *(ptmp + 1) != c)
+	    ret[i++] = *ptmp;
+	  ++ptmp;
+	}
+
+      grub_free (tmp);
+      ret[i] = '\0';
+    }
+  else
+    {
+      char *pret;
+
+      ret = grub_strdup (ptr);
+      if ((pret = grub_strchr (ret, ' ')))
+	*pret = '\0';
+    }
+
+  return ret;
+}
+
+static char*
+grub_util_default_distributor (void)
+{
+  char *cfgfile;
+  char buf[1024];
+  FILE *fp = NULL;
+  char *os_name = NULL;
+  char *os_version = NULL;
+
+  cfgfile = grub_util_path_concat (2, GRUB_SYSCONFDIR, "os-release");
+  if (!grub_util_is_regular (cfgfile))
+    {
+      grub_free (cfgfile);
+      cfgfile = grub_util_path_concat (2, "/usr/lib", "os-release");
+      if (!grub_util_is_regular (cfgfile))
+        {
+          grub_free (cfgfile);
+          return NULL;
+        }
+    }
+
+  fp = grub_util_fopen (cfgfile, "r");
+
+  if (!fp)
+    {
+      grub_util_warn (_("cannot open configuration file `%s': %s"),
+		      cfgfile, strerror (errno));
+      grub_free (cfgfile);
+      return NULL;
+    }
+
+  grub_free (cfgfile);
+
+  while (fgets (buf, sizeof (buf), fp))
+    {
+      if (buf[grub_strlen(buf) - 1] == '\n')
+	buf[grub_strlen(buf) - 1] = '\0';
+
+      if (!os_name
+	  && (os_name = os_release_get_val (buf, "NAME")))
+	continue;
+      if (!os_version
+	  && (os_version = os_release_get_val (buf, "VERSION")))
+	continue;
+      if (os_name && os_version)
+	break;
+    }
+
+  fclose (fp);
+
+  if (os_name && os_version)
+    {
+      char *os_name_version;
+
+      os_name_version = grub_xasprintf ("%s %s", os_name, os_version);
+
+      grub_free (os_name);
+      grub_free (os_version);
+
+      return os_name_version;
+    }
+
+  grub_free (os_version);
+
+  return os_name;
+}
+#endif
+
 void
 grub_util_load_config (struct grub_util_config *cfg)
 {
@@ -125,7 +250,17 @@ grub_util_load_config (struct grub_util_
       waitpid (pid, NULL, 0);
     }
   if (f)
-    return;
+    {
+#ifdef __linux__
+      if (!cfg->grub_distributor || cfg->grub_distributor[0] == '\0')
+	{
+	  if (cfg->grub_distributor)
+	    grub_free (cfg->grub_distributor);
+	  cfg->grub_distributor = grub_util_default_distributor ();
+	}
+#endif
+      return;
+    }
 
   f = grub_util_fopen (cfgfile, "r");
   if (f)
@@ -136,4 +271,13 @@ grub_util_load_config (struct grub_util_
   else
     grub_util_warn (_("cannot open configuration file `%s': %s"),
 		    cfgfile, strerror (errno));
+
+#ifdef __linux__
+  if (!cfg->grub_distributor || cfg->grub_distributor[0] == '\0')
+    {
+      if (cfg->grub_distributor)
+	grub_free (cfg->grub_distributor);
+      cfg->grub_distributor = grub_util_default_distributor ();
+    }
+#endif
 }
Index: grub-2.06/util/grub-mkconfig.in
===================================================================
--- grub-2.06.orig/util/grub-mkconfig.in
+++ grub-2.06/util/grub-mkconfig.in
@@ -225,6 +225,19 @@ GRUB_ACTUAL_DEFAULT="$GRUB_DEFAULT"
 
 if [ "x${GRUB_ACTUAL_DEFAULT}" = "xsaved" ] ; then GRUB_ACTUAL_DEFAULT="`"${grub_editenv}" - list | sed -n '/^saved_entry=/ s,^saved_entry=,,p'`" ; fi
 
+if [ x"${GRUB_DISTRIBUTOR}" = x ] ; then
+    for i in "${sysconfdir}/os-release" "/usr/lib/os-release" ; do
+      if [ -f "$i" ] ; then
+        . "$i"
+        break
+      fi
+    done
+    if [ x"${NAME}" != x ] && [ x"${VERSION}" != x ] ; then
+      GRUB_DISTRIBUTOR="${NAME} ${VERSION}"
+    else
+      GRUB_DISTRIBUTOR="${NAME}"
+    fi
+fi
 
 # These are defined in this script, export them here so that user can
 # override them.