Only use the pipe chunking protocol if we know the syslogger should

be catching stderr output, and we are not ourselves the
syslogger. Otherwise, go directly to stderr.
Bug noticed by Tom Lane.
Backpatch as far as 8.0.

Author: adunstan

src/backend/postmaster/postmaster.c

@@ -37,7 +37,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/postmaster/postmaster.c,v 1.532 2007/07/11 08:27:33 mha Exp $
+ *	  $PostgreSQL: pgsql/src/backend/postmaster/postmaster.c,v 1.533 2007/07/19 19:13:43 adunstan Exp $
  *
  * NOTES
  *
@@ -203,8 +203,8 @@ static pid_t StartupPID = 0,
 			BgWriterPID = 0,
 			AutoVacPID = 0,
 			PgArchPID = 0,
-			PgStatPID = 0;
-pid_t			SysLoggerPID = 0; /* Needs to be accessed from elog.c */
+        	PgStatPID = 0,
+    		SysLoggerPID = 0;
 
 /* Startup/shutdown state */
 #define			NoShutdown		0
@@ -218,6 +218,8 @@ static bool FatalError = false; /* T if recovering from backend crash */
 bool		ClientAuthInProgress = false;		/* T during new-client
 												 * authentication */
 
+bool redirection_done = false; 
+
 /* received START_AUTOVAC_LAUNCHER signal */
 static bool start_autovac_launcher = false;
 
@@ -332,6 +334,7 @@ typedef struct
 	InheritableSocket pgStatSock;
 	pid_t		PostmasterPid;
 	TimestampTz PgStartTime;
+	bool        redirection_done;
 #ifdef WIN32
 	HANDLE		PostmasterHandle;
 	HANDLE		initial_signal_pipe;
@@ -3953,6 +3956,8 @@ save_backend_variables(BackendParameters * param, Port *port,
 	param->PostmasterPid = PostmasterPid;
 	param->PgStartTime = PgStartTime;
 
+	param->redirection_done = redirection_done;
+
 #ifdef WIN32
 	param->PostmasterHandle = PostmasterHandle;
 	write_duplicated_handle(&param->initial_signal_pipe,
@@ -4156,6 +4161,8 @@ restore_backend_variables(BackendParameters * param, Port *port)
 	PostmasterPid = param->PostmasterPid;
 	PgStartTime = param->PgStartTime;
 
+	redirection_done = param->redirection_done;
+
 #ifdef WIN32
 	PostmasterHandle = param->PostmasterHandle;
 	pgwin32_initial_signal_pipe = param->initial_signal_pipe;

src/backend/postmaster/syslogger.c

@@ -18,7 +18,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/postmaster/syslogger.c,v 1.32 2007/06/14 01:48:51 adunstan Exp $
+ *	  $PostgreSQL: pgsql/src/backend/postmaster/syslogger.c,v 1.33 2007/07/19 19:13:43 adunstan Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -79,11 +79,12 @@ bool		Log_truncate_on_rotation = false;
  */
 bool		am_syslogger = false;
 
+extern bool redirection_done;
+
 /*
  * Private state
  */
 static pg_time_t next_rotation_time;
-static bool redirection_done = false;
 static bool pipe_eof_seen = false;
 static FILE *syslogFile = NULL;
 static char *last_file_name = NULL;
@@ -582,14 +583,12 @@ syslogger_forkexec(void)
 		snprintf(numbuf[bufc++], 32, "%d", fileno(syslogFile));
 	else
 		strcpy(numbuf[bufc++], "-1");
-	snprintf(numbuf[bufc++], 32, "%d", (int) redirection_done);
 #else							/* WIN32 */
 	if (syslogFile != NULL)
 		snprintf(numbuf[bufc++], 32, "%ld",
 				 _get_osfhandle(_fileno(syslogFile)));
 	else
 		strcpy(numbuf[bufc++], "0");
-	snprintf(numbuf[bufc++], 32, "%d", (int) redirection_done);
 #endif   /* WIN32 */
 
 	/* Add to the arg list */
@@ -623,7 +622,6 @@ syslogger_parseArgs(int argc, char *argv[])
 		syslogFile = fdopen(fd, "a");
 		setvbuf(syslogFile, NULL, LBF_MODE, 0);
 	}
-	redirection_done = (bool) atoi(*argv++);
 #else							/* WIN32 */
 	fd = atoi(*argv++);
 	if (fd != 0)
@@ -635,7 +633,6 @@ syslogger_parseArgs(int argc, char *argv[])
 			setvbuf(syslogFile, NULL, LBF_MODE, 0);
 		}
 	}
-	redirection_done = (bool) atoi(*argv++);
 #endif   /* WIN32 */
 }
 #endif   /* EXEC_BACKEND */

src/backend/utils/error/elog.c

@@ -42,7 +42,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/error/elog.c,v 1.187 2007/06/14 01:48:51 adunstan Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/error/elog.c,v 1.188 2007/07/19 19:13:43 adunstan Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -76,7 +76,7 @@ ErrorContextCallback *error_context_stack = NULL;
 
 sigjmp_buf *PG_exception_stack = NULL;
 
-extern pid_t SysLoggerPID;
+extern bool redirection_done;
 
 /* GUC parameters */
 PGErrorVerbosity Log_error_verbosity = PGERROR_VERBOSE;
@@ -1780,11 +1780,15 @@ send_message_to_server_log(ErrorData *edata)
 		 * that's really a pipe to the syslogger process. Unless we're in the
 		 * postmaster, and the syslogger process isn't started yet.
 		 */
-		if ((!Redirect_stderr || am_syslogger || (!IsUnderPostmaster && SysLoggerPID==0)) && pgwin32_is_service())
+		if (pgwin32_is_service() && (!redirection_done || am_syslogger) )
 			write_eventlog(edata->elevel, buf.data);
 		else
 #endif
-			if (Redirect_stderr)
+			/* only use the chunking protocol if we know the syslogger should
+			 * be catching stderr output, and we are not ourselves the
+			 * syslogger. Otherwise, go directly to stderr.
+			 */
+			if (redirection_done && !am_syslogger)
 				write_pipe_chunks(fileno(stderr), buf.data, buf.len);
 			else
 				write(fileno(stderr), buf.data, buf.len);