Merge 10.3 into 10.4

1 files changed, 25 insertions, 1 deletions

diff --git a/sql/item.h b/sql/item.h
index b83b997323d..c910ef9acd4 100644
--- a/sql/item.h
+++ b/sql/item.h
@@ -1576,7 +1576,14 @@ public:
     a constant expression. Used in the optimizer to propagate basic constants.
   */
   virtual bool basic_const_item() const { return 0; }
-  /*
+  /**
+    Determines if the expression is allowed as
+    a virtual column assignment source:
+      INSERT INTO t1 (vcol) VALUES (10)    -> error
+      INSERT INTO t1 (vcol) VALUES (NULL)  -> ok
+  */
+  virtual bool vcol_assignment_allowed_value() const { return false; }
+  /**
     Test if "this" is an ORDER position (rather than an expression).
     Notes:
     - can be called before fix_fields().
@@ -3591,6 +3598,7 @@ public:
     collation.set(cs, DERIVATION_IGNORABLE, MY_REPERTOIRE_ASCII);
   }
   enum Type type() const { return NULL_ITEM; }
+  bool vcol_assignment_allowed_value() const { return true; }
   double val_real();
   longlong val_int();
   String *val_str(String *str);
@@ -3837,6 +3845,21 @@ public:
   const Type_handler *type_handler() const
   { return Type_handler_hybrid_field_type::type_handler(); }
 
+  bool vcol_assignment_allowed_value() const
+  {
+    switch (state) {
+    case NULL_VALUE:
+    case DEFAULT_VALUE:
+    case IGNORE_VALUE:
+      return true;
+    case NO_VALUE:
+    case SHORT_DATA_VALUE:
+    case LONG_DATA_VALUE:
+      break;
+    }
+    return false;
+  }
+
   Field::geometry_type get_geometry_type() const
   { return Type_geometry_attributes::get_geometry_type(); };
 
@@ -6273,6 +6296,7 @@ public:
                 &null_clex_str),
      arg(NULL), cached_field(NULL) {}
   enum Type type() const { return DEFAULT_VALUE_ITEM; }
+  bool vcol_assignment_allowed_value() const { return arg == NULL; }
   bool eq(const Item *item, bool binary_cmp) const;
   bool fix_fields(THD *, Item **);
   void cleanup();