Fix bug where pink image was used instead of a thumbnail when image resize fails (#5933)

Note GD and Imagick in INSTALL file and optional installer checks.

CHANGELOG

@@ -1,6 +1,8 @@
 CHANGELOG Roundcube Webmail
 ===========================
 
+- Fix bug where pink image was used instead of a thumbnail when image resize fails (#5933)
+
 RELEASE 1.3.1
 -------------
 - Don't ignore (global) userlogins/sendmail logs in per_user_logging mode

INSTALL

@@ -16,6 +16,7 @@ REQUIREMENTS
    - PHP PDO with driver for either MySQL, PostgreSQL, SQL Server, Oracle or SQLite (required)
    - Iconv, Zip, Fileinfo, Intl, Exif (recommended)
    - LDAP for LDAP addressbook support (optional)
+   - GD, Imagick (optional thumbnails generation, QR-code)
 * PEAR and PEAR packages distributed with Roundcube or external:
    - Mail_Mime 1.10.0 or newer
    - Net_SMTP 1.7.1 or newer

installer/check.php

@@ -25,6 +25,8 @@ $optional_php_exts = array(
     'Intl'      => 'intl',
     'Exif'      => 'exif',
     'LDAP'      => 'ldap',
+    'GD'        => 'gd',
+    'Imagick'   => 'imagick',
 );
 
 $required_libs = array(
@@ -67,6 +69,8 @@ $source_urls = array(
     'oci8'      => 'http://www.php.net/manual/en/book.oci8.php',
     'PDO'       => 'http://www.php.net/manual/en/book.pdo.php',
     'LDAP'      => 'http://www.php.net/manual/en/book.ldap.php',
+    'GD'        => 'http://www.php.net/manual/en/book.image.php',
+    'Imagick'   => 'http://www.php.net/manual/en/book.imagick.php',
     'pdo_mysql'   => 'http://www.php.net/manual/en/ref.pdo-mysql.php',
     'pdo_pgsql'   => 'http://www.php.net/manual/en/ref.pdo-pgsql.php',
     'pdo_sqlite'  => 'http://www.php.net/manual/en/ref.pdo-sqlite.php',

program/steps/mail/get.inc

@@ -94,8 +94,6 @@ if (!empty($_GET['_thumb']) && $attachment->is_valid()) {
             $_GET['_thumb']     = 0;
             $_REQUEST['_embed'] = 1;
         }
-
-        unlink($orig_name);
     }
 
     if (!empty($_GET['_thumb'])) {
@@ -293,7 +291,6 @@ if (empty($_GET['_thumb']) && $attachment->is_valid()) {
                 header("Content-Length: " . filesize($file_path));
                 readfile($file_path);
             }
-            unlink($file_path);
         }
     }
     else {