From b333d7a4856853c224c4dd15efed146333c577c6 Mon Sep 17 00:00:00 2001
From: Karoly Negyesi <chx1975@gmail.com>
Date: Fri, 20 Sep 2013 04:31:24 +0200
Subject: [PATCH] act on target-dir changes during update

---
 src/Composer/Installer/LibraryInstaller.php | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/Composer/Installer/LibraryInstaller.php b/src/Composer/Installer/LibraryInstaller.php
index 281ffa11a..a754eb590 100644
--- a/src/Composer/Installer/LibraryInstaller.php
+++ b/src/Composer/Installer/LibraryInstaller.php
@@ -157,8 +157,12 @@ class LibraryInstaller implements InstallerInterface
 
     protected function updateCode(PackageInterface $initial, PackageInterface $target)
     {
-        $downloadPath = $this->getInstallPath($initial);
-        $this->downloadManager->update($initial, $target, $downloadPath);
+        $initialDownloadPath = $this->getInstallPath($initial);
+        $targetDownloadPath = $this->getInstallPath($target);
+        if ($targetDownloadPath != $initialDownloadPath) {
+            $this->filesystem->copyThenRemove($initialDownloadPath, $targetDownloadPath);
+        }
+        $this->downloadManager->update($initial, $target, $targetDownloadPath);
     }
 
     protected function removeCode(PackageInterface $package)