MDEV-7468 Fix for crash caused by connect.json_udf test

It was allowed to push UDF functions and that caused a crash.
To fix it it was forbidden to push UDF functions from HAVING into WHERE.

sql/item.cc

@@ -9108,6 +9108,23 @@ bool Item_direct_view_ref::excl_dep_on_group_fields_for_having_pushdown(st_selec
 }
 
 
+bool Item_args::excl_dep_on_group_fields_for_having_pushdown(st_select_lex *sel)
+{
+  for (uint i= 0; i < arg_count; i++)
+  {
+    if (args[i]->type() == Item::SUBSELECT_ITEM ||
+        (args[i]->type() == Item::FUNC_ITEM &&
+         ((Item_func *)args[i])->functype() == Item_func::UDF_FUNC))
+      return false;
+    if (args[i]->const_item())
+      continue;
+    if (!args[i]->excl_dep_on_group_fields_for_having_pushdown(sel))
+      return false;
+  }
+  return true;
+}
+
+
 bool Item_default_value::eq(const Item *item, bool binary_cmp) const
 {
   return item->type() == DEFAULT_VALUE_ITEM && 

sql/item.h

@@ -2523,19 +2523,7 @@ class Item_args
     }
     return true;
   }
-  bool excl_dep_on_group_fields_for_having_pushdown(st_select_lex *sel)
-  {
-    for (uint i= 0; i < arg_count; i++)
-    {
-      if (args[i]->type() == Item::SUBSELECT_ITEM)
-        return false;
-      if (args[i]->const_item())
-        continue;
-      if (!args[i]->excl_dep_on_group_fields_for_having_pushdown(sel))
-        return false;
-    }
-    return true;
-  }
+  bool excl_dep_on_group_fields_for_having_pushdown(st_select_lex *sel);
 public:
   Item_args(void)
     :args(NULL), arg_count(0)

sql/item_func.h

@@ -2327,6 +2327,8 @@ class Item_udf_func :public Item_func
   }
   bool excl_dep_on_grouping_fields(st_select_lex *sel)
   { return false; }
+  bool excl_dep_on_group_fields_for_having_pushdown(st_select_lex *sel)
+  { return false;}
 };