From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Wed, 6 Nov 2013 18:32:30 +0000 (-0500)
Subject: Prevent creating window functions with default arguments.
X-Git-Tag: REL9_0_15~25
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=352ab596fa5a8a4ceec6d308ebae34176cc09c13;p=postgresql

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/doc/src/sgml/syntax.sgml b/doc/src/sgml/syntax.sgml
index 0b1e5c4e2f..7a94870b64 100644
--- a/doc/src/sgml/syntax.sgml
+++ b/doc/src/sgml/syntax.sgml
@@ -2373,6 +2373,13 @@ SELECT concat_lower_or_upper('Hello', 'World', uppercase := true);
     having numerous parameters that have default values, named or mixed
     notation can save a great deal of writing and reduce chances for error.
    </para>
+
+   <note>
+    <para>
+     Named and mixed call notations can currently be used only with regular
+     functions, not with aggregate functions or window functions.
+    </para>
+   </note>
   </sect2>
  </sect1>
 
diff --git a/src/backend/catalog/pg_proc.c b/src/backend/catalog/pg_proc.c
index ccec1102d0..b985d63d77 100644
--- a/src/backend/catalog/pg_proc.c
+++ b/src/backend/catalog/pg_proc.c
@@ -284,6 +284,12 @@ 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.
 	 */