av array is local to the db_walk_tree stage

src/libged/facetize/tri_booleval.cpp

@@ -497,10 +497,6 @@ _ged_facetize_booleval(struct _ged_facetize_state *s, int argc, struct directory
     // Open working .g copy with BoTs replacing CSG solids and perform
     // the tree walk to set up Manifold data.  Using the working copy
     // means we will be getting the correct triangle data for each solid
-    const char **av = (const char **)bu_calloc(argc+1, sizeof(char *), "av");
-    for (int i = 0; i < argc; i++) {
-	av[i] = dpa[i]->d_namep;
-    }
     struct db_i *wdbip = db_open(wfile, DB_OPEN_READONLY);
     if (!wdbip)
 	return BRLCAD_ERROR;
@@ -509,9 +505,15 @@ _ged_facetize_booleval(struct _ged_facetize_state *s, int argc, struct directory
     db_update_nref(wdbip, &rt_uniresource);
     struct rt_wdb *wwdbp = wdb_dbopen(wdbip, RT_WDB_TYPE_DB_DEFAULT);
 
-    /* Second stage is to instance the BoTs generated by stage 1 and
-     * prepare Manifold inputs for evaluation */
+    /* Second stage is to prepare Manifold versions of the instances of the BoT
+     * obj conversions generated by stage 1.  This is where matrix placement
+     * is handled. */
     {
+	// Prepare argc/argv array for db_walk_tree
+	const char **av = (const char **)bu_calloc(argc+1, sizeof(char *), "av");
+	for (int i = 0; i < argc; i++) {
+	    av[i] = dpa[i]->d_namep;
+	}
 	struct db_tree_state init_state;
 	db_init_db_tree_state(&init_state, wdbip, wwdbp->wdb_resp);
 	/* Establish tolerances */
@@ -537,10 +539,11 @@ _ged_facetize_booleval(struct _ged_facetize_state *s, int argc, struct directory
 	} BU_UNSETJUMP;
 
 	if (i < 0) {
+	    bu_free(av, "av");
 	    return -1;
 	}
+	bu_free(av, "av");
     }
-    bu_free(av, "av");
 
     // TODO - We don't have a tree - whether that's an error or not depends
     if (!s->facetize_tree) {