Fixed segmentation fault

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@58026 15284696-431f-4ddb-bdfa-cd5b030d7da7

lib/gis/find_file.c

@@ -45,7 +45,7 @@ static const char *find_file(int misc, const char *dir,
     }
 
     if (strcmp(element, "vector") == 0 &&
-	strcasecmp(pmapset, "ogr") == 0) {
+	pmapset && strcasecmp(pmapset, "ogr") == 0) {
 	/* don't check for virtual OGR mapset */
 	return G_store(pmapset);
     }