Code review for recent changes in guc-file.l. Avoid multiple frees,

use of already-freed strings, other silliness.  Also fix reporting of
config file syntax errors so that it actually works reasonably well
(eg, points at the correct line).  Use palloc instead of malloc for
temporary storage to reduce code clutter.

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 1.237 2004/08/31 19:28:51 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.238 2004/08/31 22:43:58 tgl Exp $
  *
  *--------------------------------------------------------------------
  */
@@ -116,7 +116,6 @@ static bool assign_log_stats(bool newval, bool doit, GucSource source);
 static bool assign_transaction_read_only(bool newval, bool doit, GucSource source);
 static const char *assign_canonical_path(const char *newval, bool doit, GucSource source);
 
-static void ReadConfigFile(char *filename, GucContext context);
 
 /*
  * Debugging options
@@ -3079,7 +3078,13 @@ set_config_option(const char *name, const char *value,
 				changeValOrig = changeVal;
 
 	if (context == PGC_SIGHUP || source == PGC_S_DEFAULT)
-		elevel = DEBUG2;
+	{
+		/*
+		 * To avoid cluttering the log, only the postmaster bleats loudly
+		 * about problems with the config file.
+		 */
+		elevel = IsUnderPostmaster ? DEBUG2 : LOG;
+	}
 	else if (source == PGC_S_DATABASE || source == PGC_S_USER)
 		elevel = INFO;
 	else
@@ -4715,7 +4720,8 @@ write_nondefault_variables(GucContext context)
 
 	Assert(context == PGC_POSTMASTER || context == PGC_SIGHUP);
 	Assert(DataDir);
-	elevel = (context == PGC_SIGHUP) ? DEBUG4 : ERROR;
+
+	elevel = (context == PGC_SIGHUP) ? LOG : ERROR;
 
 	/*
 	 * Open file