Index: src/backend/utils/misc/guc-file.l
===================================================================
RCS file: /projects/cvsroot/pgsql/src/backend/utils/misc/guc-file.l,v
retrieving revision 1.37
diff -c -r1.37 guc-file.l
*** src/backend/utils/misc/guc-file.l	7 Mar 2006 01:03:12 -0000	1.37
--- src/backend/utils/misc/guc-file.l	24 May 2006 14:10:12 -0000
***************
*** 112,119 ****
  void
  ProcessConfigFile(GucContext context)
  {
! 	int			elevel;
  	struct name_value_pair *item, *head, *tail;
  
  	Assert(context == PGC_POSTMASTER || context == PGC_SIGHUP);
  
--- 112,120 ----
  void
  ProcessConfigFile(GucContext context)
  {
! 	int			elevel, i;
  	struct name_value_pair *item, *head, *tail;
+ 	char	   *env;
  
  	Assert(context == PGC_POSTMASTER || context == PGC_SIGHUP);
  
***************
*** 143,148 ****
--- 144,185 ----
  			goto cleanup_list;
  	}
  
+ 	/* Revert all options with reset source PGC_S_FILE to default value. 
+ 	 * This implementation is easier then iplementing some change flag and verify
+ 	 * what realy was commented out.  
+      * XXX When log_line_prefix is set in configuration file then log output
+      * is not correct during this phase - prefix is revert to empty value.
+      */
+ 	for (i = 0; i < num_guc_variables; i++)
+ 	{
+ 		struct config_generic *gconf = guc_variables[i];
+ 		if ( gconf->reset_source == PGC_S_FILE )
+ 		{
+ 			set_config_option(gconf->name, NULL, context,
+ 				  PGC_S_FILE, false, true);
+ 		}
+ 	}
+ 
+ 	/* Revert to environment variable. PGPORT is ignored, because it cannot be 
+ 	 * set in running state. PGC_S_FILE is used instead PGC_S_ENV so as 
+ 	 * set_config_option can override previous defined option in config file.
+ 	 * If these options are still in config file They will be overriden in 
+ 	 * the following step.
+ 	 */ 
+ 	env = getenv("PGDATESTYLE");
+ 	if (env != NULL)
+ 	{
+ 		set_config_option("datestyle", env, context, 
+ 							PGC_S_FILE, false, true);
+ 	}
+ 
+ 	env = getenv("PGCLIENTENCODING");
+ 	if (env != NULL)
+ 	{
+ 		set_config_option("client_encoding", env, context, 
+ 							PGC_S_FILE, false, true);
+ 	}
+ 
  	/* If we got here all the options checked out okay, so apply them. */
  	for (item = head; item; item = item->next)
  	{
Index: src/backend/utils/misc/guc.c
===================================================================
RCS file: /projects/cvsroot/pgsql/src/backend/utils/misc/guc.c,v
retrieving revision 1.319
diff -c -r1.319 guc.c
*** src/backend/utils/misc/guc.c	11 May 2006 19:15:35 -0000	1.319
--- src/backend/utils/misc/guc.c	24 May 2006 14:10:12 -0000
***************
*** 2648,2658 ****
  					struct config_bool *conf = (struct config_bool *) gconf;
  
  					if (conf->assign_hook)
! 						if (!(*conf->assign_hook) (conf->reset_val, true,
  												   PGC_S_DEFAULT))
  							elog(FATAL, "failed to initialize %s to %d",
! 								 conf->gen.name, (int) conf->reset_val);
! 					*conf->variable = conf->reset_val;
  					break;
  				}
  			case PGC_INT:
--- 2648,2658 ----
  					struct config_bool *conf = (struct config_bool *) gconf;
  
  					if (conf->assign_hook)
! 						if (!(*conf->assign_hook) (conf->default_val, true,
  												   PGC_S_DEFAULT))
  							elog(FATAL, "failed to initialize %s to %d",
! 								 conf->gen.name, (int) conf->default_val);
! 					*conf->variable = conf->reset_val = conf->default_val;
  					break;
  				}
  			case PGC_INT:
***************
*** 2662,2672 ****
  					Assert(conf->reset_val >= conf->min);
  					Assert(conf->reset_val <= conf->max);
  					if (conf->assign_hook)
! 						if (!(*conf->assign_hook) (conf->reset_val, true,
  												   PGC_S_DEFAULT))
  							elog(FATAL, "failed to initialize %s to %d",
! 								 conf->gen.name, conf->reset_val);
! 					*conf->variable = conf->reset_val;
  					break;
  				}
  			case PGC_REAL:
--- 2662,2672 ----
  					Assert(conf->reset_val >= conf->min);
  					Assert(conf->reset_val <= conf->max);
  					if (conf->assign_hook)
! 						if (!(*conf->assign_hook) (conf->default_val, true,
  												   PGC_S_DEFAULT))
  							elog(FATAL, "failed to initialize %s to %d",
! 								 conf->gen.name, conf->default_val);
! 					*conf->variable = conf->reset_val = conf->default_val; 
  					break;
  				}
  			case PGC_REAL:
***************
*** 2676,2686 ****
  					Assert(conf->reset_val >= conf->min);
  					Assert(conf->reset_val <= conf->max);
  					if (conf->assign_hook)
! 						if (!(*conf->assign_hook) (conf->reset_val, true,
  												   PGC_S_DEFAULT))
  							elog(FATAL, "failed to initialize %s to %g",
! 								 conf->gen.name, conf->reset_val);
! 					*conf->variable = conf->reset_val;
  					break;
  				}
  			case PGC_STRING:
--- 2676,2686 ----
  					Assert(conf->reset_val >= conf->min);
  					Assert(conf->reset_val <= conf->max);
  					if (conf->assign_hook)
! 						if (!(*conf->assign_hook) (conf->default_val, true,
  												   PGC_S_DEFAULT))
  							elog(FATAL, "failed to initialize %s to %g",
! 								 conf->gen.name, conf->default_val);
! 					*conf->variable = conf->reset_val = conf->default_val; 
  					break;
  				}
  			case PGC_STRING:
***************
*** 3647,3653 ****
  		case PGC_POSTMASTER:
  			if (context == PGC_SIGHUP)
  			{
! 				if (changeVal && !is_newvalue_equal(record, value))
  					ereport(elevel,
  							(errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
  							 errmsg("parameter \"%s\" cannot be changed after server start; configuration file change ignored",
--- 3647,3653 ----
  		case PGC_POSTMASTER:
  			if (context == PGC_SIGHUP)
  			{
! 				if (changeVal && value != NULL && !is_newvalue_equal(record, value))
  					ereport(elevel,
  							(errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
  							 errmsg("parameter \"%s\" cannot be changed after server start; configuration file change ignored",
***************
*** 3723,3729 ****
  	 * Should we set reset/stacked values?	(If so, the behavior is not
  	 * transactional.)
  	 */
! 	makeDefault = changeVal && (source <= PGC_S_OVERRIDE) && (value != NULL);
  
  	/*
  	 * Ignore attempted set if overridden by previously processed setting.
--- 3723,3729 ----
  	 * Should we set reset/stacked values?	(If so, the behavior is not
  	 * transactional.)
  	 */
! 	makeDefault = changeVal && (source <= PGC_S_OVERRIDE) && (value != NULL || source == PGC_S_FILE);
  
  	/*
  	 * Ignore attempted set if overridden by previously processed setting.
***************
*** 3766,3773 ****
  				}
  				else
  				{
! 					newval = conf->reset_val;
! 					source = conf->gen.reset_source;
  				}
  
  				if (conf->assign_hook)
--- 3766,3784 ----
  				}
  				else
  				{
! 					/* Revert value to default if source is configuration file. It is used when 
! 					 * configuration parameter is removed/commented out in the config file. Else
! 					 * RESET or SET TO DEFAULT command is called and reset_val is used. 
! 					 */
! 					if( source == PGC_S_FILE )
! 					{
! 						newval =  conf->default_val;
! 					}
! 					else
! 					{
! 						newval = conf->reset_val;
! 						source = conf->gen.reset_source;
! 					}
  				}
  
  				if (conf->assign_hook)
***************
*** 3850,3857 ****
  				}
  				else
  				{
! 					newval = conf->reset_val;
! 					source = conf->gen.reset_source;
  				}
  
  				if (conf->assign_hook)
--- 3861,3879 ----
  				}
  				else
  				{
! 					/* Revert value to default if source is configuration file. It is used when 
! 					 * configuration parameter is removed/commented out in the config file. Else
! 					 * RESET or SET TO DEFAULT command is called and reset_val is used. 
! 					 */
! 					if( source == PGC_S_FILE )
! 					{
! 						newval =  conf->default_val;
! 					}
! 					else
! 					{
! 						newval = conf->reset_val;
! 						source = conf->gen.reset_source;
! 					}
  				}
  
  				if (conf->assign_hook)
***************
*** 3934,3941 ****
  				}
  				else
  				{
! 					newval = conf->reset_val;
! 					source = conf->gen.reset_source;
  				}
  
  				if (conf->assign_hook)
--- 3956,3974 ----
  				}
  				else
  				{
! 					/* Revert value to default if source is configuration file. It is used when 
! 					 * configuration parameter is removed/commented out in the config file. Else
! 					 * RESET or SET TO DEFAULT command is called and reset_val is used. 
! 					 */
! 					if( source == PGC_S_FILE )
! 					{
! 						newval =  conf->default_val;
! 					}
! 					else
! 					{
! 						newval = conf->reset_val;
! 						source = conf->gen.reset_source;
! 					}
  				}
  
  				if (conf->assign_hook)
***************
*** 4009,4014 ****
--- 4042,4061 ----
  					if (conf->gen.flags & GUC_IS_NAME)
  						truncate_identifier(newval, strlen(newval), true);
  				}
+ 				else if (source == PGC_S_FILE)
+ 				{
+ 					/* Revert value to default when item is removed from config file. */
+ 					if ( conf->boot_val != NULL )
+ 					{
+ 						newval = guc_strdup(elevel, conf->boot_val);
+ 						if (newval == NULL)
+ 							return false;
+ 					}
+ 					else
+ 					{
+ 						return false;
+ 					}
+ 				} 
  				else if (conf->reset_val)
  				{
  					/*
***************
*** 5111,5116 ****
--- 5158,5168 ----
  static bool
  is_newvalue_equal(struct config_generic *record, const char *newvalue)
  {
+ 	if( !newvalue )
+ 	{
+ 		return false;
+ 	}
+   
  	switch (record->vartype)
  	{
  		case PGC_BOOL:
Index: src/include/utils/guc_tables.h
===================================================================
RCS file: /projects/cvsroot/pgsql/src/include/utils/guc_tables.h,v
retrieving revision 1.22
diff -c -r1.22 guc_tables.h
*** src/include/utils/guc_tables.h	5 Mar 2006 15:59:07 -0000	1.22
--- src/include/utils/guc_tables.h	24 May 2006 14:10:13 -0000
***************
*** 142,152 ****
  	/* these fields must be set correctly in initial value: */
  	/* (all but reset_val are constants) */
  	bool	   *variable;
! 	bool		reset_val;
  	GucBoolAssignHook assign_hook;
  	GucShowHook show_hook;
  	/* variable fields, initialized at runtime: */
  	bool		tentative_val;
  };
  
  struct config_int
--- 142,153 ----
  	/* these fields must be set correctly in initial value: */
  	/* (all but reset_val are constants) */
  	bool	   *variable;
! 	bool		default_val;
  	GucBoolAssignHook assign_hook;
  	GucShowHook show_hook;
  	/* variable fields, initialized at runtime: */
  	bool		tentative_val;
+ 	bool		reset_val;
  };
  
  struct config_int
***************
*** 155,167 ****
  	/* these fields must be set correctly in initial value: */
  	/* (all but reset_val are constants) */
  	int		   *variable;
! 	int			reset_val;
  	int			min;
  	int			max;
  	GucIntAssignHook assign_hook;
  	GucShowHook show_hook;
  	/* variable fields, initialized at runtime: */
  	int			tentative_val;
  };
  
  struct config_real
--- 156,169 ----
  	/* these fields must be set correctly in initial value: */
  	/* (all but reset_val are constants) */
  	int		   *variable;
! 	int			default_val;
  	int			min;
  	int			max;
  	GucIntAssignHook assign_hook;
  	GucShowHook show_hook;
  	/* variable fields, initialized at runtime: */
  	int			tentative_val;
+ 	int			reset_val;
  };
  
  struct config_real
***************
*** 170,182 ****
  	/* these fields must be set correctly in initial value: */
  	/* (all but reset_val are constants) */
  	double	   *variable;
! 	double		reset_val;
  	double		min;
  	double		max;
  	GucRealAssignHook assign_hook;
  	GucShowHook show_hook;
  	/* variable fields, initialized at runtime: */
  	double		tentative_val;
  };
  
  struct config_string
--- 172,186 ----
  	/* these fields must be set correctly in initial value: */
  	/* (all but reset_val are constants) */
  	double	   *variable;
! 	double		default_val;
  	double		min;
  	double		max;
  	GucRealAssignHook assign_hook;
  	GucShowHook show_hook;
  	/* variable fields, initialized at runtime: */
  	double		tentative_val;
+   	double		reset_val;
+  
  };
  
  struct config_string