api: add new function hdata_check_pointer

src/core/wee-hdata.c

@@ -235,6 +235,33 @@ hdata_get_list (struct t_hdata *hdata, const char *name)
     return NULL;
 }
 
+/*
+ * hdata_check_pointer: check if a pointer is valid for a given hdata/list
+ *                      return 1 if pointer exists in list
+ *                             0 if pointer does not exist
+ */
+
+int
+hdata_check_pointer (struct t_hdata *hdata, void *list, void *pointer)
+{
+    void *ptr_current;
+
+    if (hdata && list && pointer)
+    {
+        if (pointer == list)
+            return 1;
+        ptr_current = list;
+        while (ptr_current)
+        {
+            ptr_current = hdata_move (hdata, ptr_current, 1);
+            if (ptr_current && (ptr_current == pointer))
+                return 1;
+        }
+    }
+
+    return 0;
+}
+
 /*
  * hdata_move: move pointer to another element in list
  */

src/core/wee-hdata.h

@@ -61,6 +61,8 @@ extern void *hdata_get_var (struct t_hdata *hdata, void *pointer,
 extern void *hdata_get_var_at_offset (struct t_hdata *hdata, void *pointer,
                                       int offset);
 extern void *hdata_get_list (struct t_hdata *hdata, const char *name);
+extern int hdata_check_pointer (struct t_hdata *hdata, void *list,
+                                void *pointer);
 extern void *hdata_move (struct t_hdata *hdata, void *pointer, int count);
 extern char hdata_char (struct t_hdata *hdata, void *pointer,
                         const char *name);