Merge branch 'develop' into 1.7

# Conflicts:
#	composer.json

composer.json

@@ -2,7 +2,13 @@
     "name": "getgrav/grav",
     "type": "project",
     "description": "Modern, Crazy Fast, Ridiculously Easy and Amazingly Powerful Flat-File CMS",
-    "keywords": ["cms","flat-file cms","flat cms","flatfile cms","php"],
+    "keywords": [
+        "cms",
+        "flat-file cms",
+        "flat cms",
+        "flatfile cms",
+        "php"
+    ],
     "homepage": "https://getgrav.org",
     "license": "MIT",
     "require": {
@@ -16,14 +22,11 @@
         "symfony/polyfill-iconv": "^1.9",
         "symfony/polyfill-php72": "^1.9",
         "symfony/polyfill-php73": "^1.9",
-
         "psr/simple-cache": "^1.0",
         "psr/http-message": "^1.0",
         "psr/http-server-middleware": "^1.0",
-
         "kodus/psr7-server": "*",
         "nyholm/psr7": "^1.0",
-
         "twig/twig": "~1.0",
         "erusev/parsedown": "1.6.4",
         "erusev/parsedown-extra": "~0.7",
@@ -36,7 +39,6 @@
         "doctrine/collections": "^1.5",
         "guzzlehttp/psr7": "^1.4",
         "filp/whoops": "~2.2",
-
         "matthiasmullie/minify": "^1.3",
         "monolog/monolog": "~1.0",
         "gregwar/image": "2.*",
@@ -89,10 +91,14 @@
         "psr-4": {
             "Grav\\": "system/src/Grav"
         },
-        "files": ["system/defines.php"]
+        "files": [
+            "system/defines.php"
+        ]
     },
     "archive": {
-        "exclude": ["VERSION"]
+        "exclude": [
+            "VERSION"
+        ]
     },
     "scripts": {
         "api-16": "vendor/bin/phpdoc-md generate system/src > user/pages/14.api/default.16.md",

system/src/Grav/Common/Page/Page.php

@@ -1588,7 +1588,7 @@ class Page implements PageInterface
             // Get initial metadata for the page
             $metadata = array_merge($metadata, Grav::instance()['config']->get('site.metadata'));
 
-            if (isset($this->header->metadata)) {
+            if (isset($this->header->metadata) && is_array($this->header->metadata)) {
                 // Merge any site.metadata settings in with page metadata
                 $metadata = array_merge($metadata, $this->header->metadata);
             }

tests/unit/Grav/Common/Markdown/ParsedownTest.php

@@ -127,6 +127,7 @@ class ParsedownTest extends \Codeception\TestCase\Test
 
     public function testImagesSubDir()
     {
+        $this->config->set('system.images.cache_all', false);
         $this->uri->initializeWithUrlAndRootPath('http://testing.dev/subdir/item2/item2-2', '/subdir')->init();
 
         $this->assertRegexp(