Prevent creating window functions with default arguments.

Insertion of default arguments doesn't work for window functions, which is
likely to cause a crash at runtime if the implementation code doesn't check
the number of actual arguments carefully.  It doesn't seem worth working
harder than this for pre-9.2 branches.

diff --git a/src/backend/catalog/pg_proc.c b/src/backend/catalog/pg_proc.c
index 3a2c817a8b3e84c6b50dd9d5aec3de85760839b1..45d224ef409e5dd299d257f81d7a44c712b608d9 100644 (file)
--- a/src/backend/catalog/pg_proc.c
+++ b/src/backend/catalog/pg_proc.c
@@ -283,6 +283,12 @@ ProcedureCreate(const char *procedureName,
        }
    }
 
+   /* Guard against a case the planner doesn't handle yet */
+   if (isWindowFunc && parameterDefaults != NIL)
+       ereport(ERROR,
+               (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+                errmsg("window functions cannot have default arguments")));
+
    /*
     * All seems OK; prepare the data to be inserted into pg_proc.
     */