Add PQsetClientEncoding(conn, "SQL_ASCII") to the pgsql module.

[exim.git] / src / src / lookups / pgsql.c

diff --git a/src/src/lookups/pgsql.c b/src/src/lookups/pgsql.c
index a4f396d741b3ba44e96cad6fedd4089a60087f76..8b777f40b33c272ea03d6802391f6cffc456d398 100644 (file)
--- a/src/src/lookups/pgsql.c
+++ b/src/src/lookups/pgsql.c
@@ -1,10 +1,10 @@
-/* $Cambridge: exim/src/src/lookups/pgsql.c,v 1.3 2005/09/13 11:27:45 ph10 Exp $ */
+/* $Cambridge: exim/src/src/lookups/pgsql.c,v 1.6 2006/07/14 14:21:27 ph10 Exp $ */
 
 /*************************************************
 *     Exim - an Internet mail transport agent    *
 *************************************************/
 
-/* Copyright (c) University of Cambridge 1995 - 2005 */
+/* Copyright (c) University of Cambridge 1995 - 2006 */
 /* See the file NOTICE for conditions of use and distribution. */
 
 /* Thanks to Petr Cech for contributing the original code for these
@@ -247,6 +247,12 @@ if (cn == NULL)
     goto PGSQL_EXIT;
     }
 
+  /* Set the client encoding to SQL_ASCII, which means that the server will
+  not try to interpret the query as being in any fancy encoding such as UTF-8
+  or other multibyte code that might cause problems with escaping. */
+
+  PQsetClientEncoding(pg_conn, "SQL_ASCII");
+
   /* Add the connection to the cache */
 
   cn = store_get(sizeof(pgsql_connection));
@@ -422,6 +428,16 @@ to allow escaping "on spec". If you use something like "where id="ab\%cd" it
 does treat the string as "ab%cd". So we can safely quote percent and
 underscore. [This is different to MySQL, where you can't do this.]
 
+The original code quoted single quotes as \' which is documented as valid in
+the O'Reilly book "Practical PostgreSQL" (first edition) as an alternative to
+the SQL standard '' way of representing a single quote as data. However, in
+June 2006 there was some security issue with using \' and so this has been
+changed.
+
+[Note: There is a function called PQescapeStringConn() that quotes strings.
+This cannot be used because it needs a PGconn argument (the connection handle).
+Why, I don't know. Seems odd for just string escaping...]
+
 Arguments:
   s          the string to be quoted
   opt        additional option text or NULL if none
@@ -447,7 +463,12 @@ t = quoted = store_get(Ustrlen(s) + count + 1);
 
 while ((c = *s++) != 0)
   {
-  if (Ustrchr("\n\t\r\b\'\"\\%_", c) != NULL)
+  if (c == '\'')
+    {
+    *t++ = '\'';
+    *t++ = '\'';
+    }
+  else if (Ustrchr("\n\t\r\b\"\\%_", c) != NULL)
     {
     *t++ = '\\';
     switch(c)