From fa6ab166863f911e927720878763cda7e945f96d Mon Sep 17 00:00:00 2001
From: saper <saper@saper.info>
Date: Wed, 28 Mar 2012 23:23:13 +0200
Subject: [PATCH] (bug 33689) Fix incomplete query on constraints

Upgrade to 1.19 on Postgres fails due to incomplete query when trying to
defer foreign key for externallinks

* FieldInfo::conname() should return NULL not "" when constraint
  is not present
* Re-create missing constraint on schema update

Change-Id: I7ca351e07d228afdf4a5c3bef365f42a27c9ac45
---
 RELEASE-NOTES-1.20                     |  2 ++
 includes/db/DatabasePostgres.php       |  2 +-
 includes/installer/PostgresUpdater.php | 12 +++++++++---
 3 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/RELEASE-NOTES-1.20 b/RELEASE-NOTES-1.20
index d300541ec2..962d280358 100644
--- a/RELEASE-NOTES-1.20
+++ b/RELEASE-NOTES-1.20
@@ -51,6 +51,8 @@ production.
   usages of -s and -n parameters depending on compression type
 * (bug 13896) Rendering of devanagari numbers in automatic '#' number lists
 * (bug 18704) Add an unique CSS class or ID to the tagfilter table row at RecentChanges 
+* (bug 33689) Upgrade to 1.19 on Postgres fails due to incomplete query when
+              trying to defer foreign key for externallinks
 
 === API changes in 1.20 ===
 * (bug 34316) Add ability to retrieve maximum upload size from MediaWiki API.
diff --git a/includes/db/DatabasePostgres.php b/includes/db/DatabasePostgres.php
index e2b38f5203..c7d64eb2ab 100644
--- a/includes/db/DatabasePostgres.php
+++ b/includes/db/DatabasePostgres.php
@@ -18,7 +18,7 @@ class PostgresField implements Field {
 	static function fromText( $db, $table, $field ) {
 		$q = <<<SQL
 SELECT
- attnotnull, attlen, COALESCE(conname, '') AS conname,
+ attnotnull, attlen, conname AS conname,
  COALESCE(condeferred, 'f') AS deferred,
  COALESCE(condeferrable, 'f') AS deferrable,
  CASE WHEN typname = 'int2' THEN 'smallint'
diff --git a/includes/installer/PostgresUpdater.php b/includes/installer/PostgresUpdater.php
index 6b3cb514e8..9a982f9f5f 100644
--- a/includes/installer/PostgresUpdater.php
+++ b/includes/installer/PostgresUpdater.php
@@ -514,9 +514,15 @@ END;
 		}
 		$this->output( "Altering column '$table.$field' to be DEFERRABLE INITIALLY DEFERRED\n" );
 		$conname = $fi->conname();
-		$command = "ALTER TABLE $table DROP CONSTRAINT $conname";
-		$this->db->query( $command );
-		$command = "ALTER TABLE $table ADD CONSTRAINT $conname FOREIGN KEY ($field) REFERENCES $clause DEFERRABLE INITIALLY DEFERRED";
+		if ( $fi->conname() ) {
+			$conclause = "CONSTRAINT \"$conname\"";
+			$command = "ALTER TABLE $table DROP CONSTRAINT $conname";
+			$this->db->query( $command );
+		} else {
+			$this->output( "Column '$table.$field' does not have a foreign key constraint, will be added\n" );
+			$conclause = "";
+		}
+		$command = "ALTER TABLE $table ADD $conclause FOREIGN KEY ($field) REFERENCES $clause DEFERRABLE INITIALLY DEFERRED";
 		$this->db->query( $command );
 	}
 
-- 
2.20.1