8 files changed, 133 insertions, 89 deletions

diff --git a/application/Thumbnailer.php b/application/Thumbnailer.php
index 9cf5dacd..d2284e79 100644
--- a/application/Thumbnailer.php
+++ b/application/Thumbnailer.php
@@ -32,6 +32,14 @@ class Thumbnailer
     public function __construct($conf)
     {
         $this->conf = $conf;
+
+        if (! $this->checkRequirements()) {
+            $this->conf->set('thumbnails.enabled', false);
+            $this->conf->write(true);
+            // TODO: create a proper error handling system able to catch exceptions...
+            die(t('php-gd extension must be loaded to use thumbnails. Thumbnails are now disabled. Please reload the page.'));
+        }
+
         $this->wt = new WebThumbnailer();
         WTConfigManager::addFile('inc/web-thumbnailer.json');
         $this->wt->maxWidth($this->conf->get('thumbnails.width'))
@@ -57,4 +65,13 @@ class Thumbnailer
             return false;
         }
     }
+
+    /**
+     * Make sure that requirements are match to use thumbnails:
+     *   - php-gd is loaded
+     */
+    protected function checkRequirements()
+    {
+        return extension_loaded('gd');
+    }
 }
diff --git a/composer.json b/composer.json
index bdf52fcc..99ef0b5e 100644
--- a/composer.json
+++ b/composer.json
@@ -19,7 +19,7 @@
         "shaarli/netscape-bookmark-parser": "^2.0",
         "erusev/parsedown": "^1.6",
         "slim/slim": "^3.0",
-        "arthurhoaro/web-thumbnailer": "^1.0",
+        "arthurhoaro/web-thumbnailer": "^1.1",
         "pubsubhubbub/publisher": "dev-master",
         "gettext/gettext": "^4.4"
     },
diff --git a/composer.lock b/composer.lock
index 3f9ef7e2..f97a688c 100644
--- a/composer.lock
+++ b/composer.lock
@@ -1,30 +1,35 @@
 {
     "_readme": [
         "This file locks the dependencies of your project to a known state",
-        "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#composer-lock-the-lock-file",
+        "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "efa8b74ec9a15bb8c18e4a36fd13d480",
+    "content-hash": "da7a0c081b61d949154c5d2e5370cbab",
     "packages": [
         {
             "name": "arthurhoaro/web-thumbnailer",
-            "version": "v1.0.1",
+            "version": "v1.1.2",
             "source": {
                 "type": "git",
                 "url": "https://github.com/ArthurHoaro/web-thumbnailer.git",
-                "reference": "10e2919c2aa0bf55f4593c8b05508a98c79d6706"
+                "reference": "21cf6493014cb0949a7485bfc170763d964aefd4"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/ArthurHoaro/web-thumbnailer/zipball/10e2919c2aa0bf55f4593c8b05508a98c79d6706",
-                "reference": "10e2919c2aa0bf55f4593c8b05508a98c79d6706",
+                "url": "https://api.github.com/repos/ArthurHoaro/web-thumbnailer/zipball/21cf6493014cb0949a7485bfc170763d964aefd4",
+                "reference": "21cf6493014cb0949a7485bfc170763d964aefd4",
                 "shasum": ""
             },
             "require": {
                 "php": ">=5.6"
             },
+            "conflict": {
+                "phpunit/php-timer": ">=2"
+            },
             "require-dev": {
-                "phpunit/phpunit": "5.2.*"
+                "php-coveralls/php-coveralls": "^2.0",
+                "phpunit/phpunit": "5.2.*",
+                "squizlabs/php_codesniffer": "^3.2"
             },
             "type": "library",
             "autoload": {
@@ -45,7 +50,8 @@
                     "homepage": "http://hoa.ro"
                 }
             ],
-            "time": "2017-11-11T15:39:49+00:00"
+            "description": "PHP library which will retrieve a thumbnail for any given URL",
+            "time": "2018-05-05T10:32:59+00:00"
         },
         {
             "name": "container-interop/container-interop",
@@ -126,16 +132,16 @@
         },
         {
             "name": "gettext/gettext",
-            "version": "v4.4.4",
+            "version": "v4.5.0",
             "source": {
                 "type": "git",
                 "url": "https://github.com/oscarotero/Gettext.git",
-                "reference": "ab5e863de2f60806d02e6e6081e21efd45249168"
+                "reference": "81c05cb213e8e4828db7aabd9dd363367ebca9f2"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/oscarotero/Gettext/zipball/ab5e863de2f60806d02e6e6081e21efd45249168",
-                "reference": "ab5e863de2f60806d02e6e6081e21efd45249168",
+                "url": "https://api.github.com/repos/oscarotero/Gettext/zipball/81c05cb213e8e4828db7aabd9dd363367ebca9f2",
+                "reference": "81c05cb213e8e4828db7aabd9dd363367ebca9f2",
                 "shasum": ""
             },
             "require": {
@@ -184,7 +190,7 @@
                 "po",
                 "translation"
             ],
-            "time": "2018-02-21T18:49:59+00:00"
+            "time": "2018-04-23T17:22:10+00:00"
         },
         {
             "name": "gettext/languages",
@@ -639,16 +645,16 @@
         },
         {
             "name": "slim/slim",
-            "version": "3.9.2",
+            "version": "3.10.0",
             "source": {
                 "type": "git",
                 "url": "https://github.com/slimphp/Slim.git",
-                "reference": "4086d0106cf5a7135c69fce4161fe355a8feb118"
+                "reference": "d8aabeacc3688b25e2f2dd2db91df91ec6fdd748"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/slimphp/Slim/zipball/4086d0106cf5a7135c69fce4161fe355a8feb118",
-                "reference": "4086d0106cf5a7135c69fce4161fe355a8feb118",
+                "url": "https://api.github.com/repos/slimphp/Slim/zipball/d8aabeacc3688b25e2f2dd2db91df91ec6fdd748",
+                "reference": "d8aabeacc3688b25e2f2dd2db91df91ec6fdd748",
                 "shasum": ""
             },
             "require": {
@@ -706,7 +712,7 @@
                 "micro",
                 "router"
             ],
-            "time": "2017-11-26T19:13:09+00:00"
+            "time": "2018-04-19T19:29:08+00:00"
         }
     ],
     "packages-dev": [
@@ -1063,23 +1069,23 @@
         },
         {
             "name": "phpspec/prophecy",
-            "version": "1.7.5",
+            "version": "1.7.6",
             "source": {
                 "type": "git",
                 "url": "https://github.com/phpspec/prophecy.git",
-                "reference": "dfd6be44111a7c41c2e884a336cc4f461b3b2401"
+                "reference": "33a7e3c4fda54e912ff6338c48823bd5c0f0b712"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/phpspec/prophecy/zipball/dfd6be44111a7c41c2e884a336cc4f461b3b2401",
-                "reference": "dfd6be44111a7c41c2e884a336cc4f461b3b2401",
+                "url": "https://api.github.com/repos/phpspec/prophecy/zipball/33a7e3c4fda54e912ff6338c48823bd5c0f0b712",
+                "reference": "33a7e3c4fda54e912ff6338c48823bd5c0f0b712",
                 "shasum": ""
             },
             "require": {
                 "doctrine/instantiator": "^1.0.2",
                 "php": "^5.3|^7.0",
                 "phpdocumentor/reflection-docblock": "^2.0|^3.0.2|^4.0",
-                "sebastian/comparator": "^1.1|^2.0",
+                "sebastian/comparator": "^1.1|^2.0|^3.0",
                 "sebastian/recursion-context": "^1.0|^2.0|^3.0"
             },
             "require-dev": {
@@ -1122,7 +1128,7 @@
                 "spy",
                 "stub"
             ],
-            "time": "2018-02-19T10:16:54+00:00"
+            "time": "2018-04-18T13:57:24+00:00"
         },
         {
             "name": "phpunit/php-code-coverage",
@@ -2248,16 +2254,16 @@
         },
         {
             "name": "symfony/config",
-            "version": "v3.4.6",
+            "version": "v3.4.9",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/config.git",
-                "reference": "05e10567b529476a006b00746c5f538f1636810e"
+                "reference": "7c2a9d44f4433863e9bca682e7f03609234657f9"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/config/zipball/05e10567b529476a006b00746c5f538f1636810e",
-                "reference": "05e10567b529476a006b00746c5f538f1636810e",
+                "url": "https://api.github.com/repos/symfony/config/zipball/7c2a9d44f4433863e9bca682e7f03609234657f9",
+                "reference": "7c2a9d44f4433863e9bca682e7f03609234657f9",
                 "shasum": ""
             },
             "require": {
@@ -2307,20 +2313,20 @@
             ],
             "description": "Symfony Config Component",
             "homepage": "https://symfony.com",
-            "time": "2018-02-14T10:03:57+00:00"
+            "time": "2018-03-19T22:32:39+00:00"
         },
         {
             "name": "symfony/console",
-            "version": "v3.4.6",
+            "version": "v3.4.9",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/console.git",
-                "reference": "067339e9b8ec30d5f19f5950208893ff026b94f7"
+                "reference": "5b1fdfa8eb93464bcc36c34da39cedffef822cdf"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/console/zipball/067339e9b8ec30d5f19f5950208893ff026b94f7",
-                "reference": "067339e9b8ec30d5f19f5950208893ff026b94f7",
+                "url": "https://api.github.com/repos/symfony/console/zipball/5b1fdfa8eb93464bcc36c34da39cedffef822cdf",
+                "reference": "5b1fdfa8eb93464bcc36c34da39cedffef822cdf",
                 "shasum": ""
             },
             "require": {
@@ -2341,7 +2347,7 @@
                 "symfony/process": "~3.3|~4.0"
             },
             "suggest": {
-                "psr/log": "For using the console logger",
+                "psr/log-implementation": "For using the console logger",
                 "symfony/event-dispatcher": "",
                 "symfony/lock": "",
                 "symfony/process": ""
@@ -2376,20 +2382,20 @@
             ],
             "description": "Symfony Console Component",
             "homepage": "https://symfony.com",
-            "time": "2018-02-26T15:46:28+00:00"
+            "time": "2018-04-30T01:22:56+00:00"
         },
         {
             "name": "symfony/debug",
-            "version": "v3.4.6",
+            "version": "v3.4.9",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/debug.git",
-                "reference": "9b1071f86e79e1999b3d3675d2e0e7684268b9bc"
+                "reference": "1b95888cfd996484527cb41e8952d9a5eaf7454f"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/debug/zipball/9b1071f86e79e1999b3d3675d2e0e7684268b9bc",
-                "reference": "9b1071f86e79e1999b3d3675d2e0e7684268b9bc",
+                "url": "https://api.github.com/repos/symfony/debug/zipball/1b95888cfd996484527cb41e8952d9a5eaf7454f",
+                "reference": "1b95888cfd996484527cb41e8952d9a5eaf7454f",
                 "shasum": ""
             },
             "require": {
@@ -2432,20 +2438,20 @@
             ],
             "description": "Symfony Debug Component",
             "homepage": "https://symfony.com",
-            "time": "2018-02-28T21:49:22+00:00"
+            "time": "2018-04-30T16:53:52+00:00"
         },
         {
             "name": "symfony/dependency-injection",
-            "version": "v3.4.6",
+            "version": "v3.4.9",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/dependency-injection.git",
-                "reference": "12e901abc1cb0d637a0e5abe9923471361d96b07"
+                "reference": "54ff9d78b56429f9a1ac12e60bfb6d169c0468e3"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/dependency-injection/zipball/12e901abc1cb0d637a0e5abe9923471361d96b07",
-                "reference": "12e901abc1cb0d637a0e5abe9923471361d96b07",
+                "url": "https://api.github.com/repos/symfony/dependency-injection/zipball/54ff9d78b56429f9a1ac12e60bfb6d169c0468e3",
+                "reference": "54ff9d78b56429f9a1ac12e60bfb6d169c0468e3",
                 "shasum": ""
             },
             "require": {
@@ -2503,11 +2509,11 @@
             ],
             "description": "Symfony DependencyInjection Component",
             "homepage": "https://symfony.com",
-            "time": "2018-03-04T03:54:53+00:00"
+            "time": "2018-04-29T14:04:08+00:00"
         },
         {
             "name": "symfony/filesystem",
-            "version": "v3.4.6",
+            "version": "v3.4.9",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/filesystem.git",
@@ -2556,16 +2562,16 @@
         },
         {
             "name": "symfony/finder",
-            "version": "v3.4.6",
+            "version": "v3.4.9",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/finder.git",
-                "reference": "a479817ce0a9e4adfd7d39c6407c95d97c254625"
+                "reference": "bd14efe8b1fabc4de82bf50dce62f05f9a102433"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/finder/zipball/a479817ce0a9e4adfd7d39c6407c95d97c254625",
-                "reference": "a479817ce0a9e4adfd7d39c6407c95d97c254625",
+                "url": "https://api.github.com/repos/symfony/finder/zipball/bd14efe8b1fabc4de82bf50dce62f05f9a102433",
+                "reference": "bd14efe8b1fabc4de82bf50dce62f05f9a102433",
                 "shasum": ""
             },
             "require": {
@@ -2601,20 +2607,20 @@
             ],
             "description": "Symfony Finder Component",
             "homepage": "https://symfony.com",
-            "time": "2018-03-05T18:28:11+00:00"
+            "time": "2018-04-04T05:07:11+00:00"
         },
         {
             "name": "symfony/polyfill-mbstring",
-            "version": "v1.7.0",
+            "version": "v1.8.0",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/polyfill-mbstring.git",
-                "reference": "78be803ce01e55d3491c1397cf1c64beb9c1b63b"
+                "reference": "3296adf6a6454a050679cde90f95350ad604b171"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/polyfill-mbstring/zipball/78be803ce01e55d3491c1397cf1c64beb9c1b63b",
-                "reference": "78be803ce01e55d3491c1397cf1c64beb9c1b63b",
+                "url": "https://api.github.com/repos/symfony/polyfill-mbstring/zipball/3296adf6a6454a050679cde90f95350ad604b171",
+                "reference": "3296adf6a6454a050679cde90f95350ad604b171",
                 "shasum": ""
             },
             "require": {
@@ -2626,7 +2632,7 @@
             "type": "library",
             "extra": {
                 "branch-alias": {
-                    "dev-master": "1.7-dev"
+                    "dev-master": "1.8-dev"
                 }
             },
             "autoload": {
@@ -2660,20 +2666,20 @@
                 "portable",
                 "shim"
             ],
-            "time": "2018-01-30T19:27:44+00:00"
+            "time": "2018-04-26T10:06:28+00:00"
         },
         {
             "name": "symfony/yaml",
-            "version": "v3.4.6",
+            "version": "v3.4.9",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/yaml.git",
-                "reference": "6af42631dcf89e9c616242c900d6c52bd53bd1bb"
+                "reference": "033cfa61ef06ee0847e056e530201842b6e926c3"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/yaml/zipball/6af42631dcf89e9c616242c900d6c52bd53bd1bb",
-                "reference": "6af42631dcf89e9c616242c900d6c52bd53bd1bb",
+                "url": "https://api.github.com/repos/symfony/yaml/zipball/033cfa61ef06ee0847e056e530201842b6e926c3",
+                "reference": "033cfa61ef06ee0847e056e530201842b6e926c3",
                 "shasum": ""
             },
             "require": {
@@ -2718,7 +2724,7 @@
             ],
             "description": "Symfony Yaml Component",
             "homepage": "https://symfony.com",
-            "time": "2018-02-16T09:50:28+00:00"
+            "time": "2018-04-08T08:21:29+00:00"
         },
         {
             "name": "theseer/fdomdocument",
diff --git a/doc/md/Server-configuration.md b/doc/md/Server-configuration.md
index ca82b2ec..e281dc85 100644
--- a/doc/md/Server-configuration.md
+++ b/doc/md/Server-configuration.md
@@ -29,7 +29,7 @@ Extension | Required? | Usage
 ---|:---:|---
 [`openssl`](http://php.net/manual/en/book.openssl.php) | All | OpenSSL, HTTPS
 [`php-mbstring`](http://php.net/manual/en/book.mbstring.php) | CentOS, Fedora, RHEL, Windows, some hosting providers | multibyte (Unicode) string support
-[`php-gd`](http://php.net/manual/en/book.image.php) | optional | thumbnail resizing
+[`php-gd`](http://php.net/manual/en/book.image.php) | optional | required to use thumbnails
 [`php-intl`](http://php.net/manual/en/book.intl.php) | optional | localized text sorting (e.g. `e->è->f`)
 [`php-curl`](http://php.net/manual/en/book.curl.php) | optional | using cURL for fetching webpages and thumbnails in a more robust way
 [`php-gettext`](http://php.net/manual/en/book.gettext.php) | optional | Use the translation system in gettext mode (faster)
diff --git a/inc/languages/fr/LC_MESSAGES/shaarli.po b/inc/languages/fr/LC_MESSAGES/shaarli.po
index 15c8b2bb..f5189478 100644
--- a/inc/languages/fr/LC_MESSAGES/shaarli.po
+++ b/inc/languages/fr/LC_MESSAGES/shaarli.po
@@ -1,8 +1,8 @@
 msgid ""
 msgstr ""
 "Project-Id-Version: Shaarli\n"
-"POT-Creation-Date: 2018-05-05 12:47+0200\n"
-"PO-Revision-Date: 2018-05-05 12:47+0200\n"
+"POT-Creation-Date: 2018-05-05 12:48+0200\n"
+"PO-Revision-Date: 2018-05-05 12:49+0200\n"
 "Last-Translator: \n"
 "Language-Team: Shaarli\n"
 "Language: fr_FR\n"
@@ -180,6 +180,14 @@ msgstr "404 Introuvable"
 msgid "Plugin \"%s\" files not found."
 msgstr "Les fichiers de l'extension \"%s\" sont introuvables."
 
+#: application/Thumbnailer.php:40
+msgid ""
+"php-gd extension must be loaded to use thumbnails. Thumbnails are now "
+"disabled. Please reload the page."
+msgstr ""
+"php-gd extension must be loaded to use thumbnails. Thumbnails are now "
+"disabled. Please reload the page."
+
 #: application/Updater.php:76
 msgid "Couldn't retrieve Updater class methods."
 msgstr "Impossible de récupérer les méthodes de la classe Updater."
@@ -311,7 +319,7 @@ msgid "You are not supposed to change a password on an Open Shaarli."
 msgstr ""
 "Vous n'êtes pas censé modifier le mot de passe d'un Shaarli en mode ouvert."
 
-#: index.php:1070 index.php:1112 index.php:1189 index.php:1220 index.php:1325
+#: index.php:1070 index.php:1112 index.php:1190 index.php:1221 index.php:1326
 msgid "Wrong token."
 msgstr "Jeton invalide."
 
@@ -333,56 +341,56 @@ msgstr "Modification du mot de passe"
 msgid "Configuration was saved."
 msgstr "La configuration a été sauvegardé."
 
-#: index.php:1172 tmp/configure.b91ef64efc3688266305ea9b42e5017e.rtpl.php:24
+#: index.php:1173 tmp/configure.b91ef64efc3688266305ea9b42e5017e.rtpl.php:24
 msgid "Configure"
 msgstr "Configurer"
 
-#: index.php:1183 tmp/changetag.b91ef64efc3688266305ea9b42e5017e.rtpl.php:13
+#: index.php:1184 tmp/changetag.b91ef64efc3688266305ea9b42e5017e.rtpl.php:13
 #: tmp/tools.b91ef64efc3688266305ea9b42e5017e.rtpl.php:36
 msgid "Manage tags"
 msgstr "Gérer les tags"
 
-#: index.php:1201
+#: index.php:1202
 #, php-format
 msgid "The tag was removed from %d link."
 msgid_plural "The tag was removed from %d links."
 msgstr[0] "Le tag a été supprimé de %d lien."
 msgstr[1] "Le tag a été supprimé de %d liens."
 
-#: index.php:1202
+#: index.php:1203
 #, php-format
 msgid "The tag was renamed in %d link."
 msgid_plural "The tag was renamed in %d links."
 msgstr[0] "Le tag a été renommé dans %d lien."
 msgstr[1] "Le tag a été renommé dans %d liens."
 
-#: index.php:1210 tmp/addlink.b91ef64efc3688266305ea9b42e5017e.rtpl.php:13
+#: index.php:1211 tmp/addlink.b91ef64efc3688266305ea9b42e5017e.rtpl.php:13
 msgid "Shaare a new link"
 msgstr "Partager un nouveau lien"
 
-#: index.php:1385 tmp/linklist.b91ef64efc3688266305ea9b42e5017e.rtpl.php:169
+#: index.php:1386 tmp/linklist.b91ef64efc3688266305ea9b42e5017e.rtpl.php:169
 msgid "Edit"
 msgstr "Modifier"
 
-#: index.php:1385 index.php:1455
+#: index.php:1386 index.php:1456
 #: tmp/page.header.b91ef64efc3688266305ea9b42e5017e.rtpl.php:26
 #: tmp/page.header.cedf684561d925457130839629000a81.rtpl.php:26
 msgid "Shaare"
 msgstr "Shaare"
 
-#: index.php:1424
+#: index.php:1425
 msgid "Note: "
 msgstr "Note : "
 
-#: index.php:1464 tmp/export.b91ef64efc3688266305ea9b42e5017e.rtpl.php:65
+#: index.php:1465 tmp/export.b91ef64efc3688266305ea9b42e5017e.rtpl.php:65
 msgid "Export"
 msgstr "Exporter"
 
-#: index.php:1526 tmp/import.b91ef64efc3688266305ea9b42e5017e.rtpl.php:83
+#: index.php:1527 tmp/import.b91ef64efc3688266305ea9b42e5017e.rtpl.php:83
 msgid "Import"
 msgstr "Importer"
 
-#: index.php:1536
+#: index.php:1537
 #, php-format
 msgid ""
 "The file you are trying to upload is probably bigger than what this "
@@ -392,16 +400,16 @@ msgstr ""
 "le serveur web peut accepter (%s). Merci de l'envoyer en parties plus "
 "légères."
 
-#: index.php:1575 tmp/pluginsadmin.b91ef64efc3688266305ea9b42e5017e.rtpl.php:26
+#: index.php:1576 tmp/pluginsadmin.b91ef64efc3688266305ea9b42e5017e.rtpl.php:26
 #: tmp/tools.b91ef64efc3688266305ea9b42e5017e.rtpl.php:22
 msgid "Plugin administration"
 msgstr "Administration des extensions"
 
-#: index.php:1759
+#: index.php:1761
 msgid "Search: "
 msgstr "Recherche : "
 
-#: index.php:1798
+#: index.php:1800
 #, php-format
 msgid ""
 "<pre>Sessions do not seem to work correctly on your server.<br>Make sure the "
@@ -420,7 +428,7 @@ msgstr ""
 "cookies. Nous vous recommandons d'accéder à votre serveur depuis son adresse "
 "IP ou un <em>Fully Qualified Domain Name</em>.<br>"
 
-#: index.php:1808
+#: index.php:1810
 msgid "Click to try again."
 msgstr "Cliquer ici pour réessayer."
 
@@ -747,20 +755,26 @@ msgstr "Activer les miniatures"
 msgid "Warning: "
 msgstr "Attention : "
 
-#: tmp/configure.b91ef64efc3688266305ea9b42e5017e.rtpl.php:281
+#: tmp/configure.b91ef64efc3688266305ea9b42e5017e.rtpl.php:283
 msgid "It's recommended to visit the picture wall after enabling this feature."
 msgstr ""
 "Il est recommandé de visiter le Mur d'images après avoir activé cette "
 "fonctionnalité."
 
-#: tmp/configure.b91ef64efc3688266305ea9b42e5017e.rtpl.php:283
+#: tmp/configure.b91ef64efc3688266305ea9b42e5017e.rtpl.php:285
 msgid ""
 "If you have a large database, the first retrieval may take a few minutes."
 msgstr ""
 "Si vous avez beaucoup de liens, la première récupération peut prendre "
 "plusieurs minutes."
 
-#: tmp/configure.b91ef64efc3688266305ea9b42e5017e.rtpl.php:297
+#: tmp/configure.b91ef64efc3688266305ea9b42e5017e.rtpl.php:289
+msgid "You need to enable the extension <code>php-gd</code> to use thumbnails."
+msgstr ""
+"Vous devez activer l'extension <code>php-gd</code> pour utiliser les "
+"miniatures."
+
+#: tmp/configure.b91ef64efc3688266305ea9b42e5017e.rtpl.php:305
 #: tmp/editlink.b91ef64efc3688266305ea9b42e5017e.rtpl.php:72
 #: tmp/pluginsadmin.b91ef64efc3688266305ea9b42e5017e.rtpl.php:139
 #: tmp/pluginsadmin.b91ef64efc3688266305ea9b42e5017e.rtpl.php:199
diff --git a/inc/web-thumbnailer.json b/inc/web-thumbnailer.json
index 263529fd..b8db561e 100644
--- a/inc/web-thumbnailer.json
+++ b/inc/web-thumbnailer.json
@@ -1,6 +1,7 @@
 {
   "settings": {
     "default": {
+      "download_mode": "HOTLINK",
       "_comment": "infinite cache",
       "cache_duration": -1,
       "timeout": 10
diff --git a/index.php b/index.php
index 899edd67..953f1085 100644
--- a/index.php
+++ b/index.php
@@ -1036,7 +1036,7 @@ function renderPage($conf, $pluginManager, $LINKSDB, $history, $sessionManager,
             $conf->set('api.enabled', !empty($_POST['enableApi']));
             $conf->set('api.secret', escape($_POST['apiSecret']));
             $conf->set('translation.language', escape($_POST['language']));
-            $conf->set('thumbnails.enabled', !empty($_POST['enableThumbnails']));
+            $conf->set('thumbnails.enabled', extension_loaded('gd') && !empty($_POST['enableThumbnails']));
 
             try {
                 $conf->write($loginManager->isLoggedIn());
@@ -1076,6 +1076,7 @@ function renderPage($conf, $pluginManager, $LINKSDB, $history, $sessionManager,
             $PAGE->assign('api_secret', $conf->get('api.secret'));
             $PAGE->assign('languages', Languages::getAvailableLanguages());
             $PAGE->assign('language', $conf->get('translation.language'));
+            $PAGE->assign('gd_enabled', extension_loaded('gd'));
             $PAGE->assign('pagetitle', t('Configure') .' - '. $conf->get('general.title', 'Shaarli'));
             $PAGE->renderPage('configure');
             exit;
@@ -1618,6 +1619,7 @@ function buildLinkList($PAGE, $LINKSDB, $conf, $pluginManager, $loginManager)
             $elem['thumbnail'] = $thumbnailer->get($link['url']);
             $LINKSDB[$keys[$i]] = $elem;
             $updateDB = true;
+            $link['thumbnail'] = $elem['thumbnail'];
         }
 
         // Check for both signs of a note: starting with ? and 7 chars long.
diff --git a/tpl/default/configure.html b/tpl/default/configure.html
index b91fc07e..5695ae8e 100644
--- a/tpl/default/configure.html
+++ b/tpl/default/configure.html
@@ -249,8 +249,12 @@
               <span class="label-name">{'Enable thumbnails'|t}</span><br>
               <span class="label-desc">
                 {'Warning: '|t}
-                {'It\'s recommended to visit the picture wall after enabling this feature.'|t}
-                {'If you have a large database, the first retrieval may take a few minutes.'|t}
+                {if="$gd_enabled"}
+                  {'It\'s recommended to visit the picture wall after enabling this feature.'|t}
+                  {'If you have a large database, the first retrieval may take a few minutes.'|t}
+                {else}
+                  {'You need to enable the extension <code>php-gd</code> to use thumbnails.'|t}
+                {/if}
               </span>
             </label>
           </div>
@@ -258,7 +262,7 @@
         <div class="pure-u-lg-{$ratioInput} pure-u-{$ratioInputMobile}">
           <div class="form-input">
             <input type="checkbox" name="enableThumbnails" id="enableThumbnails"
-                   {if="$thumbnails_enabled"}checked{/if}/>
+                   {if="$thumbnails_enabled"}checked{/if} {if="!$gd_enabled"}disabled{/if} />
           </div>
         </div>
       </div>