From d11de8c8e7a61bccd09b42cc367a02d104b70bbb Mon Sep 17 00:00:00 2001
From: Daniel Kesselberg <mail@danielkesselberg.de>
Date: Wed, 21 Oct 2020 16:03:40 +0200
Subject: [PATCH] Add more details if extract fails.

Signed-off-by: Daniel Kesselberg <mail@danielkesselberg.de>
---
 lib/private/Archive/TAR.php | 10 ++++++++++
 lib/private/Installer.php   | 14 ++++++++------
 2 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/lib/private/Archive/TAR.php b/lib/private/Archive/TAR.php
index 0d4103299c..bf69df0edc 100644
--- a/lib/private/Archive/TAR.php
+++ b/lib/private/Archive/TAR.php
@@ -381,4 +381,14 @@ class TAR extends Archive {
 		$types = [null, 'gz', 'bz'];
 		$this->tar = new \Archive_Tar($this->path, $types[self::getTarType($this->path)]);
 	}
+
+	/**
+	 * Get error object from archive_tar.
+	 */
+	public function getError(): ?\PEAR_Error {
+		if ($this->tar instanceof \Archive_Tar && $this->tar->error_object instanceof \PEAR_Error) {
+			return $this->tar->error_object;
+		}
+		return null;
+	}
 }
diff --git a/lib/private/Installer.php b/lib/private/Installer.php
index 47d6c42d51..9388711697 100644
--- a/lib/private/Installer.php
+++ b/lib/private/Installer.php
@@ -294,12 +294,14 @@ class Installer {
 
 					if ($archive) {
 						if (!$archive->extract($extractDir)) {
-							throw new \Exception(
-								sprintf(
-									'Could not extract app %s',
-									$appId
-								)
-							);
+							$errorMessage = 'Could not extract app ' . $appId;
+
+							$archiveError = $archive->getError();
+							if ($archiveError instanceof \PEAR_Error) {
+								$errorMessage .= ': ' . $archiveError->getMessage();
+							}
+
+							throw new \Exception($errorMessage);
 						}
 						$allFiles = scandir($extractDir);
 						$folders = array_diff($allFiles, ['.', '..']);