Fix erroneous handling of shared dependencies (ie dependencies on roles)

in CREATE OR REPLACE FUNCTION.  The original code would update pg_shdepend
as if a new function was being created, even if it wasn't, with two bad
consequences: pg_shdepend might record the wrong owner for the function,
and any dependencies for roles mentioned in the function's ACL would be lost.
The fix is very easy: just don't touch pg_shdepend at all when doing a
function replacement.

Also update the CREATE FUNCTION reference page, which never explained
exactly what changes and doesn't change in a function replacement.
In passing, fix the CREATE VIEW reference page similarly; there's no
code bug there, but the docs didn't say what happens.

doc/src/sgml/ref/create_function.sgml

 <!--
-$PostgreSQL: pgsql/doc/src/sgml/ref/create_function.sgml,v 1.86 2009/09/19 10:23:26 petere Exp $
+$PostgreSQL: pgsql/doc/src/sgml/ref/create_function.sgml,v 1.87 2009/10/02 18:13:04 tgl Exp $
 -->
 
 <refentry id="SQL-CREATEFUNCTION">
@@ -562,6 +562,14 @@ CREATE FUNCTION foo(int, int default 42) ...
     <literal>USAGE</literal> privilege on the language.
    </para>
 
+   <para>
+    When <command>CREATE OR REPLACE FUNCTION</> is used to replace an
+    existing function, the ownership and permissions of the function
+    do not change.  All other function properties are assigned the
+    values specified or implied in the command.  You must own the function
+    to replace it (this includes being a member of the owning role).
+   </para>
+
  </refsect1>
 
  <refsect1 id="sql-createfunction-examples">

doc/src/sgml/ref/create_view.sgml

 <!--
-$PostgreSQL: pgsql/doc/src/sgml/ref/create_view.sgml,v 1.41 2009/01/27 12:40:15 petere Exp $
+$PostgreSQL: pgsql/doc/src/sgml/ref/create_view.sgml,v 1.42 2009/10/02 18:13:04 tgl Exp $
 PostgreSQL documentation
 -->
 
@@ -149,6 +149,14 @@ CREATE VIEW vista AS SELECT text 'Hello World' AS hello;
     used by the view.
    </para>
 
+   <para>
+    When <command>CREATE OR REPLACE VIEW</> is used on an
+    existing view, only the view's defining SELECT rule is changed.
+    Other view properties, including ownership, permissions, and non-SELECT
+    rules, remain unchanged.  You must own the view
+    to replace it (this includes being a member of the owning role).
+   </para>
+
  </refsect1>
 
  <refsect1>

src/backend/catalog/pg_proc.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/catalog/pg_proc.c,v 1.165 2009/09/22 23:43:37 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/catalog/pg_proc.c,v 1.166 2009/10/02 18:13:04 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -89,6 +89,7 @@ ProcedureCreate(const char *procedureName,
 	bool		internalInParam = false;
 	bool		internalOutParam = false;
 	Oid			variadicType = InvalidOid;
+	Oid			proowner = GetUserId();
 	Relation	rel;
 	HeapTuple	tup;
 	HeapTuple	oldtup;
@@ -290,7 +291,7 @@ ProcedureCreate(const char *procedureName,
 	namestrcpy(&procname, procedureName);
 	values[Anum_pg_proc_proname - 1] = NameGetDatum(&procname);
 	values[Anum_pg_proc_pronamespace - 1] = ObjectIdGetDatum(procNamespace);
-	values[Anum_pg_proc_proowner - 1] = ObjectIdGetDatum(GetUserId());
+	values[Anum_pg_proc_proowner - 1] = ObjectIdGetDatum(proowner);
 	values[Anum_pg_proc_prolang - 1] = ObjectIdGetDatum(languageObjectId);
 	values[Anum_pg_proc_procost - 1] = Float4GetDatum(procost);
 	values[Anum_pg_proc_prorows - 1] = Float4GetDatum(prorows);
@@ -353,7 +354,7 @@ ProcedureCreate(const char *procedureName,
 					(errcode(ERRCODE_DUPLICATE_FUNCTION),
 			errmsg("function \"%s\" already exists with same argument types",
 				   procedureName)));
-		if (!pg_proc_ownercheck(HeapTupleGetOid(oldtup), GetUserId()))
+		if (!pg_proc_ownercheck(HeapTupleGetOid(oldtup), proowner))
 			aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_PROC,
 						   procedureName);
 
@@ -471,7 +472,10 @@ ProcedureCreate(const char *procedureName,
 								procedureName)));
 		}
 
-		/* do not change existing ownership or permissions, either */
+		/*
+		 * Do not change existing ownership or permissions, either.  Note
+		 * dependency-update code below has to agree with this decision.
+		 */
 		replaces[Anum_pg_proc_proowner - 1] = false;
 		replaces[Anum_pg_proc_proacl - 1] = false;
 
@@ -498,12 +502,11 @@ ProcedureCreate(const char *procedureName,
 	/*
 	 * Create dependencies for the new function.  If we are updating an
 	 * existing function, first delete any existing pg_depend entries.
+	 * (However, since we are not changing ownership or permissions, the
+	 * shared dependencies do *not* need to change, and we leave them alone.)
 	 */
 	if (is_update)
-	{
 		deleteDependencyRecordsFor(ProcedureRelationId, retval);
-		deleteSharedDependencyRecordsFor(ProcedureRelationId, retval, 0);
-	}
 
 	myself.classId = ProcedureRelationId;
 	myself.objectId = retval;
@@ -537,7 +540,8 @@ ProcedureCreate(const char *procedureName,
 	}
 
 	/* dependency on owner */
-	recordDependencyOnOwner(ProcedureRelationId, retval, GetUserId());
+	if (!is_update)
+		recordDependencyOnOwner(ProcedureRelationId, retval, proowner);
 
 	heap_freetuple(tup);