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 79c5163..dda0b2e 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
@@ -1956,6 +1957,23 @@ renameatt(Oid myrelid,
                                 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.
         */
        if (!pg_class_ownercheck(myrelid, GetUserId()))