From 9e0fcc2ad55a36bd5fdeeb276ba8bb89d3170e97 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Sun, 23 May 2004 23:12:11 +0000
Subject: [PATCH] Avoid calling select_default_timezone() when backing out an
unwanted TZ setting. This is a temporary kluge to keep Alvaro happy;
eventually we should fix the TZ library API to make the problem really go
away.
---
src/backend/commands/variable.c | 37 ++++++++++++++++++++++++++++-----
1 file changed, 32 insertions(+), 5 deletions(-)
diff --git a/src/backend/commands/variable.c b/src/backend/commands/variable.c
index 45ed717951e..58cf97408f3 100644
--- a/src/backend/commands/variable.c
+++ b/src/backend/commands/variable.c
@@ -9,7 +9,7 @@
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/commands/variable.c,v 1.95 2004/05/21 05:07:57 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/commands/variable.c,v 1.96 2004/05/23 23:12:11 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -329,9 +329,13 @@ assign_timezone(const char *value, bool doit, GucSource source)
* Otherwise assume it is a timezone name.
*
* We have to actually apply the change before we can have any
- * hope of checking it. So, save the old value in case we
- * have to back out. We have to copy since pg_get_current_timezone
+ * hope of checking it. So, save the old value in case we have
+ * to back out. We have to copy since pg_get_current_timezone
* returns a pointer to its static state.
+ *
+ * This would all get a lot simpler if the TZ library had a better
+ * API that would let us look up and test a timezone name without
+ * making it the default.
*/
const char *cur_tz;
char *save_tz;
@@ -361,8 +365,31 @@ assign_timezone(const char *value, bool doit, GucSource source)
*/
if (save_tz)
pg_tzset(save_tz);
- else /* TZ library not initialized yet */
- select_default_timezone();
+ else
+ {
+ /*
+ * TZ library wasn't initialized yet. Annoyingly, we will
+ * come here during startup because guc-file.l checks
+ * the value with doit = false before actually applying.
+ * The best approach seems to be as follows:
+ *
+ * 1. known && acceptable: leave the setting in place,
+ * since we'll apply it soon anyway. This is mainly
+ * so that any log messages printed during this interval
+ * are timestamped with the user's requested timezone.
+ *
+ * 2. known && !acceptable: revert to GMT for lack of
+ * any better idea. (select_default_timezone() may get
+ * called later to undo this.)
+ *
+ * 3. !known: no need to do anything since TZ library
+ * did not change its state.
+ *
+ * Again, this should all go away sometime soon.
+ */
+ if (known && !acceptable)
+ pg_tzset("GMT");
+ }
/* Complain if it was bad */
if (!known)
{
--
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