From 379d7691326304b91c250faabbf252f9e257c12f Mon Sep 17 00:00:00 2001
From: Niels Keurentjes <niels.keurentjes@omines.com>
Date: Fri, 26 Feb 2016 08:38:39 +0100
Subject: [PATCH 1/2] Troubleshooting and warning in code related to issues
 with native ZipArchiver.

---
 doc/articles/troubleshooting.md           | 11 +++++++++++
 src/Composer/Downloader/ZipDownloader.php |  5 ++++-
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/doc/articles/troubleshooting.md b/doc/articles/troubleshooting.md
index ad46d7114..9582fd500 100644
--- a/doc/articles/troubleshooting.md
+++ b/doc/articles/troubleshooting.md
@@ -345,3 +345,14 @@ composer update
 ```
 
 See also https://github.com/composer/composer/issues/4180 for more information.
+
+## Zip archives are being reported as corrupted or not unpacked correctly.
+
+Composer can unpack zipballs using either a system-provided `unzip` utility or PHP's
+native `ZipArchiver` class, preferring the first. The `ZipArchiver` class however is
+known to occassionally report valid zip files as corrupted, and does not support certain
+advanced features with permissions and symlinks.
+
+If you have issues with zip files you should install a native implementation of unzip
+and verify whether the problem persists. If so it is likely a real issue in the file
+itself and you should contact the provider.
diff --git a/src/Composer/Downloader/ZipDownloader.php b/src/Composer/Downloader/ZipDownloader.php
index aaa45200b..5b29b1493 100644
--- a/src/Composer/Downloader/ZipDownloader.php
+++ b/src/Composer/Downloader/ZipDownloader.php
@@ -98,7 +98,10 @@ class ZipDownloader extends ArchiveDownloader
         }
 
         if (true !== $zipArchive->extractTo($path)) {
-            throw new \RuntimeException("There was an error extracting the ZIP file. Corrupt file?");
+            $this->io->writeError("<warn>As there is no 'unzip' command installed zip files are being unpacked using the PHP zip extension.</warn>");
+            $this->io->writeError("<warn> This may cause invalid reports of corrupted archives. Installing 'unzip' may remediate them.</warn>");
+
+            throw new \RuntimeException("There was an error extracting the ZIP file, it is either corrupted or using an invalid format");
         }
 
         $zipArchive->close();

From d60e0c1842d37be25cd31658a54da127158573d2 Mon Sep 17 00:00:00 2001
From: Niels Keurentjes <niels.keurentjes@omines.com>
Date: Fri, 26 Feb 2016 14:45:19 +0100
Subject: [PATCH 2/2] Accidentally indented.

---
 src/Composer/Downloader/ZipDownloader.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Composer/Downloader/ZipDownloader.php b/src/Composer/Downloader/ZipDownloader.php
index 5b29b1493..5278be91b 100644
--- a/src/Composer/Downloader/ZipDownloader.php
+++ b/src/Composer/Downloader/ZipDownloader.php
@@ -99,7 +99,7 @@ class ZipDownloader extends ArchiveDownloader
 
         if (true !== $zipArchive->extractTo($path)) {
             $this->io->writeError("<warn>As there is no 'unzip' command installed zip files are being unpacked using the PHP zip extension.</warn>");
-            $this->io->writeError("<warn> This may cause invalid reports of corrupted archives. Installing 'unzip' may remediate them.</warn>");
+            $this->io->writeError("<warn>This may cause invalid reports of corrupted archives. Installing 'unzip' may remediate them.</warn>");
 
             throw new \RuntimeException("There was an error extracting the ZIP file, it is either corrupted or using an invalid format");
         }