Bug#14140927 IS_EQUALS() IS BOGUS FOR FIELD_GEOM, HURTING IN-PLACE ALTER

Alexander Barkov · Alexander Barkov · commit 99240937c101 · 2012-08-14T11:54:01.000+04:00
Problem: IN-PLACE ALTER TABLE did not work for tables having
at least one GEOMETRY column:
Field_geom::is_equal() was missing, so the inherited Field_blob::is_equal()
was called for GEOMETRY columns, which never returned "true".

Fix: implementing a proper is_equal() for Field_geom.
diff --git a/sql/field.cc b/sql/field.cc
@@ -8236,6 +8236,17 @@ Field_geom::store(const char *from, uint length, const CHARSET_INFO *cs)
   return TYPE_ERR_BAD_VALUE;
 }
 
+
+uint Field_geom::is_equal(Create_field *new_field)
+{
+  return new_field->field_flags_are_binary() == field_flags_are_binary() &&
+         new_field->sql_type == real_type() &&
+         new_field->geom_type == get_geometry_type() &&
+         new_field->charset == field_charset &&
+         new_field->pack_length == pack_length();
+}
+
+
 #endif /*HAVE_SPATIAL*/
 
 /****************************************************************************
diff --git a/sql/field.h b/sql/field.h
@@ -3473,6 +3473,7 @@ class Field_geom :public Field_blob {
     DBUG_ASSERT(type() == MYSQL_TYPE_GEOMETRY);
     return new Field_geom(*this);
   }
+  uint is_equal(Create_field *new_field);
 };
 #endif /*HAVE_SPATIAL*/
 

Original file line number	Diff line number	Diff line change
`@@ -3473,6 +3473,7 @@ class Field_geom :public Field_blob {`
`3473`	`3473`	`DBUG_ASSERT(type() == MYSQL_TYPE_GEOMETRY);`
`3474`	`3474`	`return new Field_geom(*this);`
`3475`	`3475`	`}`
	`3476`	`+ uint is_equal(Create_field *new_field);`
`3476`	`3477`	`};`
`3477`	`3478`	`#endif /HAVE_SPATIAL/`
`3478`	`3479`