>From 11c7bad562dbf744681827044ac73d697a583ce9 Mon Sep 17 00:00:00 2001
From: Alvaro Herrera <alvherre@alvh.no-ip.org>
Date: Thu, 25 Sep 2014 16:34:50 -0300
Subject: [PATCH 02/42] deparse/core: return affected attnum in RENAME

The various ALTER OBJECT RENAME already return the OID of the affected
object, but when it is a column being renamed, we were lacking its
attnum to properly identify it for later processing.  This patch doesn't
change any user-visible behavior, but the attnum is available for later
patches.
---
 src/backend/commands/alter.c     |  7 +++++--
 src/backend/commands/tablecmds.c | 26 +++++++++++++++++---------
 src/backend/tcop/utility.c       |  4 ++--
 src/include/commands/alter.h     |  2 +-
 src/include/commands/tablecmds.h |  2 +-
 5 files changed, 26 insertions(+), 15 deletions(-)

diff --git a/src/backend/commands/alter.c b/src/backend/commands/alter.c
index 78b54b4..dfd57e0 100644
--- a/src/backend/commands/alter.c
+++ b/src/backend/commands/alter.c
@@ -299,9 +299,12 @@ AlterObjectRename_internal(Relation rel, Oid objectId, const char *new_name)
 /*
  * Executes an ALTER OBJECT / RENAME TO statement.  Based on the object
  * type, the function appropriate to that type is executed.
+ *
+ * Return value is the OID of the renamed object.  The objectSubId, if any,
+ * is returned in objsubid.
  */
 Oid
-ExecRenameStmt(RenameStmt *stmt)
+ExecRenameStmt(RenameStmt *stmt, int *objsubid)
 {
 	switch (stmt->renameType)
 	{
@@ -331,7 +334,7 @@ ExecRenameStmt(RenameStmt *stmt)
 
 		case OBJECT_COLUMN:
 		case OBJECT_ATTRIBUTE:
-			return renameatt(stmt);
+			return renameatt(stmt, objsubid);
 
 		case OBJECT_RULE:
 			return RenameRewriteRule(stmt->relation, stmt->subname,
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 66d5083..1ee2901 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -2155,8 +2155,10 @@ renameatt_check(Oid myrelid, Form_pg_class classform, bool recursing)
 
 /*
  *		renameatt_internal		- workhorse for renameatt
+ *
+ * Return value is the column number of the attribute in the 'myrelid' relation.
  */
-static void
+static int
 renameatt_internal(Oid myrelid,
 				   const char *oldattname,
 				   const char *newattname,
@@ -2297,6 +2299,8 @@ renameatt_internal(Oid myrelid,
 	heap_close(attrelation, RowExclusiveLock);
 
 	relation_close(targetrelation, NoLock);		/* close rel but keep lock */
+
+	return attnum;
 }
 
 /*
@@ -2321,9 +2325,10 @@ RangeVarCallbackForRenameAttribute(const RangeVar *rv, Oid relid, Oid oldrelid,
  *		renameatt		- changes the name of a attribute in a relation
  */
 Oid
-renameatt(RenameStmt *stmt)
+renameatt(RenameStmt *stmt, int *objsubid)
 {
 	Oid			relid;
+	int			attnum;
 
 	/* lock level taken here should match renameatt_internal */
 	relid = RangeVarGetRelidExtended(stmt->relation, AccessExclusiveLock,
@@ -2339,13 +2344,16 @@ renameatt(RenameStmt *stmt)
 		return InvalidOid;
 	}
 
-	renameatt_internal(relid,
-					   stmt->subname,	/* old att name */
-					   stmt->newname,	/* new att name */
-					   interpretInhOption(stmt->relation->inhOpt),		/* recursive? */
-					   false,	/* recursing? */
-					   0,		/* expected inhcount */
-					   stmt->behavior);
+	attnum =
+		renameatt_internal(relid,
+						   stmt->subname,	/* old att name */
+						   stmt->newname,	/* new att name */
+						   interpretInhOption(stmt->relation->inhOpt), /* recursive? */
+						   false,	/* recursing? */
+						   0,		/* expected inhcount */
+						   stmt->behavior);
+	if (objsubid)
+		*objsubid = attnum;
 
 	/* This is an ALTER TABLE command so it's about the relid */
 	return relid;
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 3533cfa..88dcd47 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -805,7 +805,7 @@ standard_ProcessUtility(Node *parsetree,
 									   context, params,
 									   dest, completionTag);
 				else
-					ExecRenameStmt(stmt);
+					ExecRenameStmt(stmt, NULL);
 			}
 			break;
 
@@ -1304,7 +1304,7 @@ ProcessUtilitySlow(Node *parsetree,
 				break;
 
 			case T_RenameStmt:
-				ExecRenameStmt((RenameStmt *) parsetree);
+				ExecRenameStmt((RenameStmt *) parsetree, NULL);
 				break;
 
 			case T_AlterObjectSchemaStmt:
diff --git a/src/include/commands/alter.h b/src/include/commands/alter.h
index 14d24f1..0382037 100644
--- a/src/include/commands/alter.h
+++ b/src/include/commands/alter.h
@@ -18,7 +18,7 @@
 #include "nodes/parsenodes.h"
 #include "utils/relcache.h"
 
-extern Oid	ExecRenameStmt(RenameStmt *stmt);
+extern Oid	ExecRenameStmt(RenameStmt *stmt, int *objsubid);
 
 extern Oid	ExecAlterObjectSchemaStmt(AlterObjectSchemaStmt *stmt);
 extern Oid AlterObjectNamespace_oid(Oid classId, Oid objid, Oid nspOid,
diff --git a/src/include/commands/tablecmds.h b/src/include/commands/tablecmds.h
index a55e8d4..c6e75e4 100644
--- a/src/include/commands/tablecmds.h
+++ b/src/include/commands/tablecmds.h
@@ -53,7 +53,7 @@ extern void ExecuteTruncate(TruncateStmt *stmt);
 
 extern void SetRelationHasSubclass(Oid relationId, bool relhassubclass);
 
-extern Oid	renameatt(RenameStmt *stmt);
+extern Oid	renameatt(RenameStmt *stmt, int *attnum);
 
 extern Oid	RenameConstraint(RenameStmt *stmt);
 
-- 
2.1.4