From 167291206e57ffb9bc043308682061e5e499ff45 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Tim=20D=C3=BCsterhus?= <duesterhus@woltlab.com>
Date: Tue, 3 Aug 2021 16:13:58 +0200
Subject: [PATCH] Take the array key into account when matching up FOREIGN KEYs
 in DatabaseTableChangeProcessor
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Previously a FOREIGN KEY within the database that looks like this:

    […] FOREIGN KEY (someOtherUserID) REFERENCES wcf1_user (userID) […]

would match up a FOREIGN KEY definition like the following:

    […] FOREIGN KEY (userID) REFERENCES wcf1_user (userID) […]

Converted into the `getDiffData()` representation of the PHP DDL API these
would like:

    [ 'columns'           => 'someOtherUserID'
    , 'referencedColumns' => 'userID'
    , 'referencedTable'   => 'wcf1_user'
    ]

and

    [ 'columns'           => 'userID'
    , 'referencedColumns' => 'userID'
    , 'referencedTable'   => 'wcf1_user'
    ]

respectively.

Now taking the diff of the second array against the first array (subtracting
the first from the second) will remove *both* 'userID' values, resulting in an
empty difference, thus believing both FOREIGN KEYs are identical

Fix this issue by using `array_diff_assoc` which will also take the key into
account.
---
 .../database/table/DatabaseTableChangeProcessor.class.php       | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/wcfsetup/install/files/lib/system/database/table/DatabaseTableChangeProcessor.class.php b/wcfsetup/install/files/lib/system/database/table/DatabaseTableChangeProcessor.class.php
index 87fc5051e4..ec604781a6 100644
--- a/wcfsetup/install/files/lib/system/database/table/DatabaseTableChangeProcessor.class.php
+++ b/wcfsetup/install/files/lib/system/database/table/DatabaseTableChangeProcessor.class.php
@@ -427,7 +427,7 @@ class DatabaseTableChangeProcessor {
 				foreach ($table->getForeignKeys() as $foreignKey) {
 					$matchingExistingForeignKey = null;
 					foreach ($existingForeignKeys as $existingForeignKey) {
-						if (empty(array_diff($foreignKey->getDiffData(), $existingForeignKey->getDiffData()))) {
+						if (empty(array_diff_assoc($foreignKey->getDiffData(), $existingForeignKey->getDiffData()))) {
 							$matchingExistingForeignKey = $existingForeignKey;
 							break;
 						}
-- 
2.20.1