Avoid calling ckalloc on a length 0 buffer

flightaware · Jul 11, 2019 · f173602 · f173602
1 parent 72de4fb
commit f173602
Showing 1 changed file with 11 additions and 7 deletions.
diff --git a/generic/zookeepertcl.c b/generic/zookeepertcl.c
@@ -1598,15 +1598,19 @@ zootcl_children_subcommand(Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv[],
  }
 
  int count = strings ? strings->count : 0;
- Tcl_Obj **listObjv = (Tcl_Obj **)ckalloc (sizeof(Tcl_Obj *) * count);
+ if (count > 0) {
+ Tcl_Obj **listObjv = (Tcl_Obj **)ckalloc (sizeof(Tcl_Obj *) * count);
 
- for (i = 0; i < count; i++) {
- listObjv[i] = Tcl_NewStringObj (strings->data[i], -1);
- }
+ for (i = 0; i < count; i++) {
+ listObjv[i] = Tcl_NewStringObj (strings->data[i], -1);
+ }
+
+ Tcl_Obj *listObj = Tcl_NewListObj (count, listObjv);
+ Tcl_SetObjResult (interp, listObj);
+ } else {
+ Tcl_SetObjResult (interp, Tcl_NewListObj (count, NULL)); 
+ }
 
- Tcl_Obj *listObj = Tcl_NewListObj (count, listObjv);
-
- Tcl_SetObjResult (interp, listObj);
  ckfree (strings);
  } else {
  zootcl_callbackContext *ztc = (zootcl_callbackContext *)ckalloc (sizeof (zootcl_callbackContext));