When we are in error recursion trouble, arrange to suppress translation and

encoding conversion of any elog/ereport message being sent to the frontend.
This generalizes a patch that I put in last October, which suppressed
translation of only specific messages known to be associated with recursive
can't-translate-the-message behavior.  As shown in bug #4680, we need a more
general answer in order to have some hope of coping with broken encoding
conversion setups.  This approach seems a good deal less klugy anyway.

Patch in all supported branches.

1 files changed, 31 insertions, 2 deletions

diff --git a/src/backend/libpq/pqformat.c b/src/backend/libpq/pqformat.c
index 46e75c5e049..7736b2e3a42 100644
--- a/src/backend/libpq/pqformat.c
+++ b/src/backend/libpq/pqformat.c
@@ -24,7 +24,7 @@
  * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- *	$PostgreSQL: pgsql/src/backend/libpq/pqformat.c,v 1.40 2005/10/15 02:49:18 momjian Exp $
+ *	$PostgreSQL: pgsql/src/backend/libpq/pqformat.c,v 1.40.2.1 2009/03/02 21:19:05 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -41,6 +41,7 @@
  *		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_ascii_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
@@ -188,7 +189,6 @@ void
 pq_sendstring(StringInfo buf, const char *str)
 {
 	int			slen = strlen(str);
-
 	char	   *p;
 
 	p = pg_server_to_client(str, slen);
@@ -203,6 +203,35 @@ pq_sendstring(StringInfo buf, const char *str)
 }
 
 /* --------------------------------
+ *		pq_send_ascii_string	- append a null-terminated text string (without conversion)
+ *
+ * This function intentionally bypasses encoding conversion, instead just
+ * silently replacing any non-7-bit-ASCII characters with question marks.
+ * It is used only when we are having trouble sending an error message to
+ * the client with normal localization and encoding conversion.  The caller
+ * should already have taken measures to ensure the string is just ASCII;
+ * the extra work here is just to make certain we don't send a badly encoded
+ * string to the client (which might or might not be robust about that).
+ *
+ * NB: passed text string must be null-terminated, and so is the data
+ * sent to the frontend.
+ * --------------------------------
+ */
+void
+pq_send_ascii_string(StringInfo buf, const char *str)
+{
+	while (*str)
+	{
+		char	ch = *str++;
+
+		if (IS_HIGHBIT_SET(ch))
+			ch = '?';
+		appendStringInfoCharMacro(buf, ch);
+	}
+	appendStringInfoChar(buf, '\0');
+}
+
+/* --------------------------------
  *		pq_sendint		- append a binary integer to a StringInfo buffer
  * --------------------------------
  */