Fix problem with infinite recursion between write_syslogger_file and

elog if the former has trouble writing its file.  Code review for
Magnus' patch to redirect stderr to syslog on Windows (Bruce's version
seems right, but did some minor prettification).

Backpatch both changes to 8.0 branch.

src/backend/postmaster/syslogger.c

@@ -18,7 +18,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/postmaster/syslogger.c,v 1.13 2005/03/10 07:14:03 neilc Exp $
+ *	  $PostgreSQL: pgsql/src/backend/postmaster/syslogger.c,v 1.14 2005/03/12 01:54:44 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -679,10 +679,9 @@ write_syslogger_file_binary(const char *buffer, int count)
 	LeaveCriticalSection(&sysfileSection);
 #endif
 
+	/* can't use ereport here because of possible recursion */
 	if (rc != count)
-		ereport(LOG,
-				(errcode_for_file_access(),
-				 errmsg("could not write to log file: %m")));
+		write_stderr("could not write to log file: %s\n", strerror(errno));
 }
 
 #ifdef WIN32

src/backend/utils/error/elog.c

@@ -42,7 +42,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/error/elog.c,v 1.157 2005/02/27 01:02:57 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/error/elog.c,v 1.158 2005/03/12 01:54:44 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1557,7 +1557,6 @@ send_message_to_server_log(ErrorData *edata)
 		appendStringInfoChar(&buf, '\n');
 	}
 
-
 #ifdef HAVE_SYSLOG
 	/* Write to syslog, if enabled */
 	if (Log_destination & LOG_DESTINATION_SYSLOG)
@@ -1597,7 +1596,9 @@ send_message_to_server_log(ErrorData *edata)
 		write_syslog(syslog_level, buf.data);
 	}
 #endif   /* HAVE_SYSLOG */
+
 #ifdef WIN32
+	/* Write to eventlog, if enabled */
 	if (Log_destination & LOG_DESTINATION_EVENTLOG)
 	{
 		int			eventlog_level;
@@ -1628,19 +1629,23 @@ send_message_to_server_log(ErrorData *edata)
 		write_eventlog(eventlog_level, buf.data);
 	}
 #endif   /* WIN32 */
+
 	/* Write to stderr, if enabled */
 	if ((Log_destination & LOG_DESTINATION_STDERR) || whereToSendOutput == Debug)
 	{
 #ifdef WIN32
-		/* In a win32 service environment, there is no usable stderr. Capture
-		   anything going there and write it to the eventlog instead.
-		   If stderr redirection is active, leave it to stderr because the
-		   logger will capture it to a file. */
+		/*
+		 * In a win32 service environment, there is no usable stderr. Capture
+		 * anything going there and write it to the eventlog instead.
+		 *
+		 * If stderr redirection is active, it's ok to write to stderr
+		 * because that's really a pipe to the syslogger process.
+		 */
 		if ((!Redirect_stderr || am_syslogger) && pgwin32_is_service())
 			write_eventlog(EVENTLOG_ERROR_TYPE, buf.data);
 		else
 #endif
-		fprintf(stderr, "%s", buf.data);
+			fprintf(stderr, "%s", buf.data);
 	}
 
 	/* If in the syslogger process, try to write messages direct to file */