core plugin isXDot: take parameter as a const

This function does not modify its input.

diff --git a/plugin/core/gvrender_core_json.c b/plugin/core/gvrender_core_json.c
index 69c117cba77dc980458a3a65a36cdc29d58950ab..148d88bba75e384f0e5c43eb8b7b537080803522 100644 (file)
--- a/plugin/core/gvrender_core_json.c
+++ b/plugin/core/gvrender_core_json.c
@@ -330,8 +330,7 @@ static void write_xdots (char * val, GVJ_t * job, state_t* sp)
     freeXDot(cmds);
 }
 
-static int isXDot (char* name)
-{
+static int isXDot(const char* name) {
   return streq(name, "_draw_") || streq(name, "_ldraw_") ||
          streq(name, "_hdraw_") || streq(name, "_tdraw_") ||
          streq(name, "_hldraw_") || streq(name, "_tldraw_");