Index: src/backend/libpq/pqformat.c
===================================================================
RCS file: /cvsroot/pgsql/src/backend/libpq/pqformat.c,v
retrieving revision 1.48
diff -c -r1.48 pqformat.c
*** src/backend/libpq/pqformat.c	1 Jan 2009 17:23:42 -0000	1.48
--- src/backend/libpq/pqformat.c	2 Mar 2009 19:13:12 -0000
***************
*** 41,46 ****
--- 41,47 ----
   *		pq_sendcountedtext - append a counted text string (with character set conversion)
   *		pq_sendtext		- append a text string (with conversion)
   *		pq_sendstring	- append a null-terminated text string (with conversion)
+  *		pq_send_raw_string - append a null-terminated text string (without conversion)
   *		pq_endmessage	- send the completed message to the frontend
   * Note: it is also possible to append data to the StringInfo buffer using
   * the regular StringInfo routines, but this is discouraged since required
***************
*** 184,190 ****
  pq_sendstring(StringInfo buf, const char *str)
  {
  	int			slen = strlen(str);
- 
  	char	   *p;
  
  	p = pg_server_to_client(str, slen);
--- 185,190 ----
***************
*** 199,204 ****
--- 199,221 ----
  }
  
  /* --------------------------------
+  *		pq_send_raw_string	- append a null-terminated text string (without conversion)
+  *
+  * This function intentionally bypasses encoding conversion; it should be used
+  * only in very specialized cases, preferable only when the given string is
+  * known to be just 7-bit ASCII.
+  *
+  * NB: passed text string must be null-terminated, and so is the data
+  * sent to the frontend.
+  * --------------------------------
+  */
+ void
+ pq_send_raw_string(StringInfo buf, const char *str)
+ {
+ 	appendBinaryStringInfo(buf, str, strlen(str) + 1);
+ }
+ 
+ /* --------------------------------
   *		pq_sendint		- append a binary integer to a StringInfo buffer
   * --------------------------------
   */
Index: src/backend/utils/error/elog.c
===================================================================
RCS file: /cvsroot/pgsql/src/backend/utils/error/elog.c,v
retrieving revision 1.212
diff -c -r1.212 elog.c
*** src/backend/utils/error/elog.c	19 Jan 2009 15:34:23 -0000	1.212
--- src/backend/utils/error/elog.c	2 Mar 2009 19:13:13 -0000
***************
*** 72,77 ****
--- 72,80 ----
  #include "utils/ps_status.h"
  
  
+ #undef _
+ #define _(x) err_gettext(x)
+ 
  /* Global variables */
  ErrorContextCallback *error_context_stack = NULL;
  
***************
*** 165,170 ****
--- 168,192 ----
  }
  
  /*
+  * One of those fallback steps is to stop trying to localize the error
+  * message, since there's a significant probability that that's exactly
+  * what's causing the recursion.
+  */
+ static inline const char *
+ err_gettext(const char *str)
+ {
+ #ifdef ENABLE_NLS
+ 	if (in_error_recursion_trouble())
+ 		return str;
+ 	else
+ 		return gettext(str);
+ #else
+ 	return str;
+ #endif
+ }
+ 
+ 
+ /*
   * errstart --- begin an error-reporting cycle
   *
   * Create a stack entry and store the given parameters in it.  Subsequently,
***************
*** 631,637 ****
  		char		   *fmtbuf; \
  		StringInfoData	buf; \
  		/* Internationalize the error format string */ \
! 		if (translateit) \
  			fmt = dgettext(edata->domain, fmt); \
  		/* Expand %m in format string */ \
  		fmtbuf = expand_fmt_string(fmt, edata); \
--- 653,659 ----
  		char		   *fmtbuf; \
  		StringInfoData	buf; \
  		/* Internationalize the error format string */ \
! 		if (translateit && !in_error_recursion_trouble()) \
  			fmt = dgettext(edata->domain, fmt); \
  		/* Expand %m in format string */ \
  		fmtbuf = expand_fmt_string(fmt, edata); \
***************
*** 2137,2143 ****
  		}
  		else
  		{
! 			char	   *msg = _("Not safe to send CSV data\n");
  
  			write(fileno(stderr), msg, strlen(msg));
  			if (!(Log_destination & LOG_DESTINATION_STDERR) &&
--- 2159,2165 ----
  		}
  		else
  		{
! 			const char *msg = _("Not safe to send CSV data\n");
  
  			write(fileno(stderr), msg, strlen(msg));
  			if (!(Log_destination & LOG_DESTINATION_STDERR) &&
***************
*** 2190,2195 ****
--- 2212,2237 ----
  
  
  /*
+  * Append a text string to the error report being built for the client.
+  *
+  * This is ordinarily identical to pq_sendstring(), but if we are in
+  * error recursion trouble we skip encoding conversion, because of the
+  * possibility that the problem is a failure in the encoding conversion
+  * subsystem itself.  Code elsewhere should ensure that the passed-in
+  * strings will be plain 7-bit ASCII, and thus not in need of conversion,
+  * in such cases.  (In particular, we disable localization of error messages
+  * to help ensure that's true.)
+  */
+ static void
+ err_sendstring(StringInfo buf, const char *str)
+ {
+ 	if (in_error_recursion_trouble())
+ 		pq_send_raw_string(buf, str);
+ 	else
+ 		pq_sendstring(buf, str);
+ }
+ 
+ /*
   * Write error report to client
   */
  static void
***************
*** 2208,2214 ****
  		int			i;
  
  		pq_sendbyte(&msgbuf, PG_DIAG_SEVERITY);
! 		pq_sendstring(&msgbuf, error_severity(edata->elevel));
  
  		/* unpack MAKE_SQLSTATE code */
  		ssval = edata->sqlerrcode;
--- 2250,2256 ----
  		int			i;
  
  		pq_sendbyte(&msgbuf, PG_DIAG_SEVERITY);
! 		err_sendstring(&msgbuf, error_severity(edata->elevel));
  
  		/* unpack MAKE_SQLSTATE code */
  		ssval = edata->sqlerrcode;
***************
*** 2220,2238 ****
  		tbuf[i] = '\0';
  
  		pq_sendbyte(&msgbuf, PG_DIAG_SQLSTATE);
! 		pq_sendstring(&msgbuf, tbuf);
  
  		/* M field is required per protocol, so always send something */
  		pq_sendbyte(&msgbuf, PG_DIAG_MESSAGE_PRIMARY);
  		if (edata->message)
! 			pq_sendstring(&msgbuf, edata->message);
  		else
! 			pq_sendstring(&msgbuf, _("missing error text"));
  
  		if (edata->detail)
  		{
  			pq_sendbyte(&msgbuf, PG_DIAG_MESSAGE_DETAIL);
! 			pq_sendstring(&msgbuf, edata->detail);
  		}
  
  		/* detail_log is intentionally not used here */
--- 2262,2280 ----
  		tbuf[i] = '\0';
  
  		pq_sendbyte(&msgbuf, PG_DIAG_SQLSTATE);
! 		err_sendstring(&msgbuf, tbuf);
  
  		/* M field is required per protocol, so always send something */
  		pq_sendbyte(&msgbuf, PG_DIAG_MESSAGE_PRIMARY);
  		if (edata->message)
! 			err_sendstring(&msgbuf, edata->message);
  		else
! 			err_sendstring(&msgbuf, _("missing error text"));
  
  		if (edata->detail)
  		{
  			pq_sendbyte(&msgbuf, PG_DIAG_MESSAGE_DETAIL);
! 			err_sendstring(&msgbuf, edata->detail);
  		}
  
  		/* detail_log is intentionally not used here */
***************
*** 2240,2291 ****
  		if (edata->hint)
  		{
  			pq_sendbyte(&msgbuf, PG_DIAG_MESSAGE_HINT);
! 			pq_sendstring(&msgbuf, edata->hint);
  		}
  
  		if (edata->context)
  		{
  			pq_sendbyte(&msgbuf, PG_DIAG_CONTEXT);
! 			pq_sendstring(&msgbuf, edata->context);
  		}
  
  		if (edata->cursorpos > 0)
  		{
  			snprintf(tbuf, sizeof(tbuf), "%d", edata->cursorpos);
  			pq_sendbyte(&msgbuf, PG_DIAG_STATEMENT_POSITION);
! 			pq_sendstring(&msgbuf, tbuf);
  		}
  
  		if (edata->internalpos > 0)
  		{
  			snprintf(tbuf, sizeof(tbuf), "%d", edata->internalpos);
  			pq_sendbyte(&msgbuf, PG_DIAG_INTERNAL_POSITION);
! 			pq_sendstring(&msgbuf, tbuf);
  		}
  
  		if (edata->internalquery)
  		{
  			pq_sendbyte(&msgbuf, PG_DIAG_INTERNAL_QUERY);
! 			pq_sendstring(&msgbuf, edata->internalquery);
  		}
  
  		if (edata->filename)
  		{
  			pq_sendbyte(&msgbuf, PG_DIAG_SOURCE_FILE);
! 			pq_sendstring(&msgbuf, edata->filename);
  		}
  
  		if (edata->lineno > 0)
  		{
  			snprintf(tbuf, sizeof(tbuf), "%d", edata->lineno);
  			pq_sendbyte(&msgbuf, PG_DIAG_SOURCE_LINE);
! 			pq_sendstring(&msgbuf, tbuf);
  		}
  
  		if (edata->funcname)
  		{
  			pq_sendbyte(&msgbuf, PG_DIAG_SOURCE_FUNCTION);
! 			pq_sendstring(&msgbuf, edata->funcname);
  		}
  
  		pq_sendbyte(&msgbuf, '\0');		/* terminator */
--- 2282,2333 ----
  		if (edata->hint)
  		{
  			pq_sendbyte(&msgbuf, PG_DIAG_MESSAGE_HINT);
! 			err_sendstring(&msgbuf, edata->hint);
  		}
  
  		if (edata->context)
  		{
  			pq_sendbyte(&msgbuf, PG_DIAG_CONTEXT);
! 			err_sendstring(&msgbuf, edata->context);
  		}
  
  		if (edata->cursorpos > 0)
  		{
  			snprintf(tbuf, sizeof(tbuf), "%d", edata->cursorpos);
  			pq_sendbyte(&msgbuf, PG_DIAG_STATEMENT_POSITION);
! 			err_sendstring(&msgbuf, tbuf);
  		}
  
  		if (edata->internalpos > 0)
  		{
  			snprintf(tbuf, sizeof(tbuf), "%d", edata->internalpos);
  			pq_sendbyte(&msgbuf, PG_DIAG_INTERNAL_POSITION);
! 			err_sendstring(&msgbuf, tbuf);
  		}
  
  		if (edata->internalquery)
  		{
  			pq_sendbyte(&msgbuf, PG_DIAG_INTERNAL_QUERY);
! 			err_sendstring(&msgbuf, edata->internalquery);
  		}
  
  		if (edata->filename)
  		{
  			pq_sendbyte(&msgbuf, PG_DIAG_SOURCE_FILE);
! 			err_sendstring(&msgbuf, edata->filename);
  		}
  
  		if (edata->lineno > 0)
  		{
  			snprintf(tbuf, sizeof(tbuf), "%d", edata->lineno);
  			pq_sendbyte(&msgbuf, PG_DIAG_SOURCE_LINE);
! 			err_sendstring(&msgbuf, tbuf);
  		}
  
  		if (edata->funcname)
  		{
  			pq_sendbyte(&msgbuf, PG_DIAG_SOURCE_FUNCTION);
! 			err_sendstring(&msgbuf, edata->funcname);
  		}
  
  		pq_sendbyte(&msgbuf, '\0');		/* terminator */
***************
*** 2316,2322 ****
  
  		appendStringInfoChar(&buf, '\n');
  
! 		pq_sendstring(&msgbuf, buf.data);
  
  		pfree(buf.data);
  	}
--- 2358,2364 ----
  
  		appendStringInfoChar(&buf, '\n');
  
! 		err_sendstring(&msgbuf, buf.data);
  
  		pfree(buf.data);
  	}
***************
*** 2430,2439 ****
  
  /*
   * error_severity --- get localized string representing elevel
-  *
-  * Note: in an error recursion situation, we stop localizing the tags
-  * for ERROR and above.  This is necessary because the problem might be
-  * failure to convert one of these strings to the client encoding.
   */
  static const char *
  error_severity(int elevel)
--- 2472,2477 ----
***************
*** 2463,2484 ****
  			prefix = _("WARNING");
  			break;
  		case ERROR:
! 			if (in_error_recursion_trouble())
! 				prefix = "ERROR";
! 			else
! 				prefix = _("ERROR");
  			break;
  		case FATAL:
! 			if (in_error_recursion_trouble())
! 				prefix = "FATAL";
! 			else
! 				prefix = _("FATAL");
  			break;
  		case PANIC:
! 			if (in_error_recursion_trouble())
! 				prefix = "PANIC";
! 			else
! 				prefix = _("PANIC");
  			break;
  		default:
  			prefix = "???";
--- 2501,2513 ----
  			prefix = _("WARNING");
  			break;
  		case ERROR:
! 			prefix = _("ERROR");
  			break;
  		case FATAL:
! 			prefix = _("FATAL");
  			break;
  		case PANIC:
! 			prefix = _("PANIC");
  			break;
  		default:
  			prefix = "???";
Index: src/backend/utils/mb/wchar.c
===================================================================
RCS file: /cvsroot/pgsql/src/backend/utils/mb/wchar.c,v
retrieving revision 1.71
diff -c -r1.71 wchar.c
*** src/backend/utils/mb/wchar.c	10 Feb 2009 19:29:39 -0000	1.71
--- src/backend/utils/mb/wchar.c	2 Mar 2009 19:13:13 -0000
***************
*** 1636,1660 ****
  	for (j = 0; j < jlimit; j++)
  		p += sprintf(p, "%02x", (unsigned char) mbstr[j]);
  
! 	/*
! 	 * In an error recursion situation, don't try to translate the message.
! 	 * This gets us out of trouble if the problem is failure to convert
! 	 * this very message (after translation) to the client encoding.
! 	 */
! 	if (in_error_recursion_trouble())
! 		ereport(ERROR,
! 				(errcode(ERRCODE_UNTRANSLATABLE_CHARACTER),
! 				 errmsg_internal("character 0x%s of encoding \"%s\" has no equivalent in \"%s\"",
! 								 buf,
! 								 pg_enc2name_tbl[src_encoding].name,
! 								 pg_enc2name_tbl[dest_encoding].name)));
! 	else
! 		ereport(ERROR,
! 				(errcode(ERRCODE_UNTRANSLATABLE_CHARACTER),
! 				 errmsg("character 0x%s of encoding \"%s\" has no equivalent in \"%s\"",
! 						buf,
! 						pg_enc2name_tbl[src_encoding].name,
! 						pg_enc2name_tbl[dest_encoding].name)));
  }
  
  #endif
--- 1636,1647 ----
  	for (j = 0; j < jlimit; j++)
  		p += sprintf(p, "%02x", (unsigned char) mbstr[j]);
  
! 	ereport(ERROR,
! 			(errcode(ERRCODE_UNTRANSLATABLE_CHARACTER),
! 			 errmsg("character 0x%s of encoding \"%s\" has no equivalent in \"%s\"",
! 					buf,
! 					pg_enc2name_tbl[src_encoding].name,
! 					pg_enc2name_tbl[dest_encoding].name)));
  }
  
  #endif
Index: src/include/libpq/pqformat.h
===================================================================
RCS file: /cvsroot/pgsql/src/include/libpq/pqformat.h,v
retrieving revision 1.27
diff -c -r1.27 pqformat.h
*** src/include/libpq/pqformat.h	1 Jan 2009 17:23:59 -0000	1.27
--- src/include/libpq/pqformat.h	2 Mar 2009 19:13:13 -0000
***************
*** 22,27 ****
--- 22,28 ----
  				   bool countincludesself);
  extern void pq_sendtext(StringInfo buf, const char *str, int slen);
  extern void pq_sendstring(StringInfo buf, const char *str);
+ extern void pq_send_raw_string(StringInfo buf, const char *str);
  extern void pq_sendint(StringInfo buf, int i, int b);
  extern void pq_sendint64(StringInfo buf, int64 i);
  extern void pq_sendfloat4(StringInfo buf, float4 f);