Index: src/backend/executor/spi.c
===================================================================
RCS file: /projects/cvsroot/pgsql/src/backend/executor/spi.c,v
retrieving revision 1.131
diff -u -r1.131 spi.c
--- src/backend/executor/spi.c	13 Oct 2004 01:25:10 -0000	1.131
+++ src/backend/executor/spi.c	13 Aug 2005 19:50:40 -0000
@@ -70,6 +70,12 @@
 	 */
 	if (_SPI_curid != _SPI_connected)
 		return SPI_ERROR_CONNECT;
+		
+	/* You can't actually execute queries if there is no current
+	 * snapshot, so return an error straightaway. eg User defined type
+	 * input functions */
+	if (SerializableSnapshot == NULL)
+		return SPI_ERROR_CONNECT;
 
 	if (_SPI_stack == NULL)
 	{
Index: doc/src/sgml/spi.sgml
===================================================================
RCS file: /projects/cvsroot/pgsql/doc/src/sgml/spi.sgml,v
retrieving revision 1.42
diff -u -r1.42 spi.sgml
--- doc/src/sgml/spi.sgml	29 Jul 2005 13:00:03 -0000	1.42
+++ doc/src/sgml/spi.sgml	13 Aug 2005 19:50:40 -0000
@@ -106,6 +106,13 @@
    <function>SPI_finish</function> are forbidden.
    (But see <function>SPI_push</function> and <function>SPI_pop</function>.)
   </para>
+
+  <para> 
+   <function>SPI_connect</function> will also fail if there is no current
+   snapshot. This generally only happens in implicitly called functions such
+   as type input functions.
+  </para>
+
  </refsect1>
 
  <refsect1>