Index: doc/src/sgml/ref/alter_user.sgml
===================================================================
RCS file: /cvsroot/pgsql-server/doc/src/sgml/ref/alter_user.sgml,v
retrieving revision 1.32
diff -c -c -r1.32 alter_user.sgml
*** doc/src/sgml/ref/alter_user.sgml	29 Nov 2003 19:51:38 -0000	1.32
--- doc/src/sgml/ref/alter_user.sgml	27 Apr 2004 00:29:56 -0000
***************
*** 57,62 ****
--- 57,64 ----
     The second variant changes the name of the user.  Only a database
     superuser can rename user accounts.  The session user cannot be
     renamed.  (Connect as a different user if you need to do that.)
+    Because <literal>MD5</>-encrypted passwords use the username as
+    cryptographic salt, renaming a user clears their password.
    </para>
  
    <para>
Index: src/backend/commands/user.c
===================================================================
RCS file: /cvsroot/pgsql-server/src/backend/commands/user.c,v
retrieving revision 1.139
diff -c -c -r1.139 user.c
*** src/backend/commands/user.c	16 Mar 2004 05:05:57 -0000	1.139
--- src/backend/commands/user.c	27 Apr 2004 00:29:57 -0000
***************
*** 959,966 ****
  				(errcode(ERRCODE_UNDEFINED_OBJECT),
  				 errmsg("user \"%s\" does not exist", stmt->user)));
  
! 	if (!(superuser()
! 	 || ((Form_pg_shadow) GETSTRUCT(oldtuple))->usesysid == GetUserId()))
  		ereport(ERROR,
  				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
  				 errmsg("permission denied")));
--- 959,966 ----
  				(errcode(ERRCODE_UNDEFINED_OBJECT),
  				 errmsg("user \"%s\" does not exist", stmt->user)));
  
! 	if (!(superuser() ||
! 	    ((Form_pg_shadow) GETSTRUCT(oldtuple))->usesysid == GetUserId()))
  		ereport(ERROR,
  				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
  				 errmsg("permission denied")));
***************
*** 1157,1172 ****
  void
  RenameUser(const char *oldname, const char *newname)
  {
! 	HeapTuple	tup;
  	Relation	rel;
! 
  	/* ExclusiveLock because we need to update the password file */
  	rel = heap_openr(ShadowRelationName, ExclusiveLock);
  
! 	tup = SearchSysCacheCopy(SHADOWNAME,
  							 CStringGetDatum(oldname),
  							 0, 0, 0);
! 	if (!HeapTupleIsValid(tup))
  		ereport(ERROR,
  				(errcode(ERRCODE_UNDEFINED_OBJECT),
  				 errmsg("user \"%s\" does not exist", oldname)));
--- 1157,1177 ----
  void
  RenameUser(const char *oldname, const char *newname)
  {
! 	HeapTuple	oldtuple,
! 				newtuple;
  	Relation	rel;
! 	Datum		repl_val[Natts_pg_shadow];
! 	char		repl_null[Natts_pg_shadow];
! 	char		repl_repl[Natts_pg_shadow];
! 	int			i;
! 	
  	/* ExclusiveLock because we need to update the password file */
  	rel = heap_openr(ShadowRelationName, ExclusiveLock);
  
! 	oldtuple = SearchSysCache(SHADOWNAME,
  							 CStringGetDatum(oldname),
  							 0, 0, 0);
! 	if (!HeapTupleIsValid(oldtuple))
  		ereport(ERROR,
  				(errcode(ERRCODE_UNDEFINED_OBJECT),
  				 errmsg("user \"%s\" does not exist", oldname)));
***************
*** 1177,1183 ****
  	 * not be an actual problem besides a little confusion, so think about
  	 * this and decide.
  	 */
! 	if (((Form_pg_shadow) GETSTRUCT(tup))->usesysid == GetSessionUserId())
  		ereport(ERROR,
  				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
  				 errmsg("session user may not be renamed")));
--- 1182,1188 ----
  	 * not be an actual problem besides a little confusion, so think about
  	 * this and decide.
  	 */
! 	if (((Form_pg_shadow) GETSTRUCT(oldtuple))->usesysid == GetSessionUserId())
  		ereport(ERROR,
  				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
  				 errmsg("session user may not be renamed")));
***************
*** 1196,1208 ****
  				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
  				 errmsg("must be superuser to rename users")));
  
! 	/* rename */
! 	namestrcpy(&(((Form_pg_shadow) GETSTRUCT(tup))->usename), newname);
! 	simple_heap_update(rel, &tup->t_self, tup);
! 	CatalogUpdateIndexes(rel, tup);
  
  	heap_close(rel, NoLock);
- 	heap_freetuple(tup);
  
  	user_file_update_needed = true;
  }
--- 1201,1231 ----
  				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
  				 errmsg("must be superuser to rename users")));
  
! 	for (i = 0; i < Natts_pg_shadow; i++)
! 		repl_repl[i] = ' ';
! 
! 	repl_repl[Anum_pg_shadow_usename - 1] = 'r';
! 	repl_val[Anum_pg_shadow_usename - 1] = DirectFunctionCall1(namein,
! 											CStringGetDatum(newname));
! 	repl_null[Anum_pg_shadow_usename - 1] = ' ';
  
+ 	if (!heap_attisnull(oldtuple, Anum_pg_shadow_passwd))
+ 	{
+ 		/* MD5 uses the username as salt, so just clear it on a rename */
+ 		repl_repl[Anum_pg_shadow_passwd - 1] = 'r';
+ 		repl_null[Anum_pg_shadow_passwd - 1] = 'n';
+ 	
+ 		ereport(NOTICE,
+ 			(errmsg("password cleared because of user rename")));
+ 	}
+ 			 
+ 	newtuple = heap_modifytuple(oldtuple, rel, repl_val, repl_null, repl_repl);
+ 	simple_heap_update(rel, &oldtuple->t_self, newtuple);
+ 	
+ 	CatalogUpdateIndexes(rel, newtuple);
+ 
+ 	ReleaseSysCache(oldtuple);
  	heap_close(rel, NoLock);
  
  	user_file_update_needed = true;
  }