Forbid renaming columns of objects whose column names are system-generated.

KaiGai Kohei, with adjustments to the comments.

diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 79c5163e61b929a8cc49ad3366443b7c4480800b..dda0b2e847eab35046a59e556b2269ae2aa38c3f 100644 (file)
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *   $PostgreSQL: pgsql/src/backend/commands/tablecmds.c,v 1.328 2010/03/10 19:48:39 rhaas Exp $
+ *   $PostgreSQL: pgsql/src/backend/commands/tablecmds.c,v 1.329 2010/03/20 00:43:42 rhaas Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1943,6 +1943,7 @@ renameatt(Oid myrelid,
    HeapTuple   atttup;
    Form_pg_attribute attform;
    int         attnum;
+   char        relkind;
 
    /*
     * Grab an exclusive lock on the target table, which we will NOT release
@@ -1955,6 +1956,23 @@ renameatt(Oid myrelid,
                (errcode(ERRCODE_WRONG_OBJECT_TYPE),
                 errmsg("cannot rename column of typed table")));
 
+   /*
+    * Renaming the columns of sequences or toast tables doesn't actually
+    * break anything from the system's point of view, since internal
+    * references are by attnum.  But it doesn't seem right to allow users
+    * to change names that are hardcoded into the system, hence the following
+    * restriction.
+    */
+   relkind = RelationGetForm(targetrelation)->relkind;
+   if (relkind != RELKIND_RELATION &&
+       relkind != RELKIND_VIEW &&
+       relkind != RELKIND_COMPOSITE_TYPE &&
+       relkind != RELKIND_INDEX)
+       ereport(ERROR,
+               (errcode(ERRCODE_WRONG_OBJECT_TYPE),
+                errmsg("\"%s\" is not a table, view, composite type or index",
+                       RelationGetRelationName(targetrelation))));
+
    /*
     * permissions checking.  only the owner of a class can change its schema.
     */