*** pgsql/src/backend/utils/misc/guc.c	2008/11/19 01:10:23	1.478
--- pgsql/src/backend/utils/misc/guc.c	2008/11/19 02:07:07	1.479
***************
*** 10,16 ****
   * Written by Peter Eisentraut <peter_e@gmx.net>.
   *
   * IDENTIFICATION
!  *	  $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.477 2008/11/11 02:42:32 tgl Exp $
   *
   *--------------------------------------------------------------------
   */
--- 10,16 ----
   * Written by Peter Eisentraut <peter_e@gmx.net>.
   *
   * IDENTIFICATION
!  *	  $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.478 2008/11/19 01:10:23 tgl Exp $
   *
   *--------------------------------------------------------------------
   */
*************** define_custom_variable(struct config_gen
*** 5657,5662 ****
--- 5657,5663 ----
  	const char **nameAddr = &name;
  	const char *value;
  	struct config_string *pHolder;
+ 	GucContext phcontext;
  	struct config_generic **res;
  
  	/*
*************** define_custom_variable(struct config_gen
*** 5703,5708 ****
--- 5704,5731 ----
  	*res = variable;
  
  	/*
+ 	 * Infer context for assignment based on source of existing value.
+ 	 * We can't tell this with exact accuracy, but we can at least do
+ 	 * something reasonable in typical cases.
+ 	 */
+ 	switch (pHolder->gen.source)
+ 	{
+ 		case PGC_S_DEFAULT:
+ 		case PGC_S_ENV_VAR:
+ 		case PGC_S_FILE:
+ 		case PGC_S_ARGV:
+ 			phcontext = PGC_SIGHUP;
+ 			break;
+ 		case PGC_S_DATABASE:
+ 		case PGC_S_USER:
+ 		case PGC_S_CLIENT:
+ 		case PGC_S_SESSION:
+ 		default:
+ 			phcontext = PGC_USERSET;
+ 			break;
+ 	}
+ 
+ 	/*
  	 * Assign the string value stored in the placeholder to the real variable.
  	 *
  	 * XXX this is not really good enough --- it should be a nontransactional
*************** define_custom_variable(struct config_gen
*** 5713,5719 ****
  
  	if (value)
  		set_config_option(name, value,
! 						  pHolder->gen.context, pHolder->gen.source,
  						  GUC_ACTION_SET, true);
  
  	/*
--- 5736,5742 ----
  
  	if (value)
  		set_config_option(name, value,
! 						  phcontext, pHolder->gen.source,
  						  GUC_ACTION_SET, true);
  
  	/*