Fix crash caused by log_timezone patch if we attempt to emit any elog messages

between the setting of log_line_prefix and the setting of log_timezone.  We
can't realistically set log_timezone any earlier than we do now, so the best
behavior seems to be to use GMT zone if any timestamps are to be logged during
early startup.  Create a dummy zone variable with a minimal definition of GMT
(in particular it will never know about leap seconds), so that we can set it
up without reference to any external files.

2 files changed, 26 insertions, 5 deletions

diff --git a/src/backend/utils/error/elog.c b/src/backend/utils/error/elog.c
index d51dd0bf1af..44d02752080 100644
--- a/src/backend/utils/error/elog.c
+++ b/src/backend/utils/error/elog.c
@@ -42,7 +42,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/error/elog.c,v 1.192 2007/08/04 01:26:54 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/error/elog.c,v 1.193 2007/08/04 19:29:25 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1497,16 +1497,25 @@ log_line_prefix(StringInfo buf)
 				{
 					struct timeval tv;
 					pg_time_t	stamp_time;
+					pg_tz	   *tz;
 					char		strfbuf[128],
 								msbuf[8];
 
 					gettimeofday(&tv, NULL);
 					stamp_time = (pg_time_t) tv.tv_sec;
 
+					/*
+					 * Normally we print log timestamps in log_timezone, but
+					 * during startup we could get here before that's set.
+					 * If so, fall back to gmt_timezone (which guc.c ensures
+					 * is set up before Log_line_prefix can become nonempty).
+					 */
+					tz = log_timezone ? log_timezone : gmt_timezone;
+
 					pg_strftime(strfbuf, sizeof(strfbuf),
 								/* leave room for milliseconds... */
 								"%Y-%m-%d %H:%M:%S     %Z",
-								pg_localtime(&stamp_time, log_timezone));
+								pg_localtime(&stamp_time, tz));
 
 					/* 'paste' milliseconds into place... */
 					sprintf(msbuf, ".%03d", (int) (tv.tv_usec / 1000));
@@ -1518,22 +1527,28 @@ log_line_prefix(StringInfo buf)
 			case 't':
 				{
 					pg_time_t	stamp_time = (pg_time_t) time(NULL);
+					pg_tz	   *tz;
 					char		strfbuf[128];
 
+					tz = log_timezone ? log_timezone : gmt_timezone;
+
 					pg_strftime(strfbuf, sizeof(strfbuf),
 								"%Y-%m-%d %H:%M:%S %Z",
-								pg_localtime(&stamp_time, log_timezone));
+								pg_localtime(&stamp_time, tz));
 					appendStringInfoString(buf, strfbuf);
 				}
 				break;
 			case 's':
 				{
 					pg_time_t	stamp_time = (pg_time_t) MyStartTime;
+					pg_tz	   *tz;
 					char		strfbuf[128];
 
+					tz = log_timezone ? log_timezone : gmt_timezone;
+
 					pg_strftime(strfbuf, sizeof(strfbuf),
 								"%Y-%m-%d %H:%M:%S %Z",
-								pg_localtime(&stamp_time, log_timezone));
+								pg_localtime(&stamp_time, tz));
 					appendStringInfoString(buf, strfbuf);
 				}
 				break;
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index fc35b14cf3f..45fef6d7a31 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -10,7 +10,7 @@
  * Written by Peter Eisentraut <peter_e@gmx.net>.
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.409 2007/08/04 01:26:54 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.410 2007/08/04 19:29:25 tgl Exp $
  *
  *--------------------------------------------------------------------
  */
@@ -2927,6 +2927,12 @@ InitializeGUCOptions(void)
 	long		stack_rlimit;
 
 	/*
+	 * Before log_line_prefix could possibly receive a nonempty setting,
+	 * make sure that timezone processing is minimally alive (see elog.c).
+	 */
+	pg_timezone_pre_initialize();
+
+	/*
 	 * Build sorted array of all GUC variables.
 	 */
 	build_guc_variables();