SPI_cursor_open failed to enforce that only read-only queries could be

executed in read_only mode.  This could lead to various relatively-subtle
failures, such as an allegedly stable function returning non-stable results.
Bug goes all the way back to the introduction of read-only mode in 8.0.
Per report from Gaetano Mendola.

diff --git a/src/backend/executor/spi.c b/src/backend/executor/spi.c
index dd1fcf8ec11a7a5dfb53a84773fa952bda8902f5..71e40ed25b4435f5733f3e53fb4a3c03d02c7efb 100644 (file)
--- a/src/backend/executor/spi.c
+++ b/src/backend/executor/spi.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/executor/spi.c,v 1.133.4.1 2005/02/10 20:36:48 tgl Exp $
+ *       $PostgreSQL: pgsql/src/backend/executor/spi.c,v 1.133.4.2 2007/03/17 03:16:03 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -862,6 +862,16 @@ SPI_cursor_open(const char *name, void *plan,
                        break;
        }
 
+       /*
+        * If told to be read-only, we'd better check for read-only queries.
+        */
+       if (read_only && !QueryIsReadOnly(queryTree))
+               ereport(ERROR,
+                               (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+                                /* translator: %s is a SQL statement name */
+                                errmsg("%s is not allowed in a non-volatile function",
+                                               CreateQueryTag(queryTree))));
+
        /* Reset SPI result */
        SPI_processed = 0;
        SPI_tuptable = NULL;