diff --git a/CHANGELOG b/CHANGELOG
index eb75f3a26..a45196470 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -163,6 +163,9 @@
 
 * 1.38.0 (2019-XX-XX)
 
+ * fixed batch filter clobbers array keys when fill parameter is used
+ * added preserveKeys support for the batch filter
+ * fixed "embed" support when used from "template_from_string"
  * added the possibility to pass a TemplateWrapper to Twig\Environment::load()
  * improved the performance of the sandbox
  * added a spaceless filter
diff --git a/src/Environment.php b/src/Environment.php
index 82afadc4a..b577c737b 100644
--- a/src/Environment.php
+++ b/src/Environment.php
@@ -299,7 +299,7 @@ class Environment
     {
         $key = $this->getLoader()->getCacheKey($name).$this->optionsHash;
 
-        return $this->templateClassPrefix.hash('sha256', $key).(null === $index ? '' : '_'.$index);
+        return $this->templateClassPrefix.hash('sha256', $key).(null === $index ? '' : '___'.$index);
     }
 
     /**
@@ -379,9 +379,17 @@ class Environment
      */
     public function loadTemplate($name, $index = null)
     {
-        $cls = $mainCls = $this->getTemplateClass($name);
+        return $this->loadClass($this->getTemplateClass($name), $name, $index);
+    }
+
+    /**
+     * @internal
+     */
+    public function loadClass($cls, $name, $index = null)
+    {
+        $mainCls = $cls;
         if (null !== $index) {
-            $cls .= '_'.$index;
+            $cls .= '___'.$index;
         }
 
         if (isset($this->loadedTemplates[$cls])) {
@@ -411,7 +419,7 @@ class Environment
                 }
 
                 if (!class_exists($cls, false)) {
-                    throw new RuntimeError(sprintf('Failed to load Twig template "%s", index "%s": cache is corrupted.', $name, $index), -1, $source);
+                    throw new RuntimeError(sprintf('Failed to load Twig template "%s", index "%s": cache might be corrupted.', $name, $index), -1, $source);
                 }
             }
         }
diff --git a/src/Extension/CoreExtension.php b/src/Extension/CoreExtension.php
index 5d5ad3e4b..04d367dc7 100644
--- a/src/Extension/CoreExtension.php
+++ b/src/Extension/CoreExtension.php
@@ -1469,23 +1469,22 @@ function twig_constant_is_defined($constant, $object = null)
  *
  * @return array
  */
-function twig_array_batch($items, $size, $fill = null)
+function twig_array_batch($items, $size, $fill = null, $preserveKeys = true)
 {
     if ($items instanceof \Traversable) {
-        $items = iterator_to_array($items, false);
+        $items = iterator_to_array($items, $preserveKeys);
     }
 
     $size = ceil($size);
 
-    $result = array_chunk($items, $size, true);
+    $result = array_chunk($items, $size, $preserveKeys);
 
-    if (null !== $fill && !empty($result)) {
+    if (null !== $fill && $result) {
         $last = \count($result) - 1;
         if ($fillCount = $size - \count($result[$last])) {
-            $result[$last] = array_merge(
-                $result[$last],
-                array_fill(0, $fillCount, $fill)
-            );
+            for ($i = 0; $i < $fillCount; $i++) {
+                $result[$last][] = $fill;
+            }
         }
     }
 
diff --git a/src/NodeTraverser.php b/src/NodeTraverser.php
index fc483a07f..e4146fc0b 100644
--- a/src/NodeTraverser.php
+++ b/src/NodeTraverser.php
@@ -39,10 +39,6 @@ final class NodeTraverser
 
     public function addVisitor(NodeVisitorInterface $visitor)
     {
-        if (!isset($this->visitors[$visitor->getPriority()])) {
-            $this->visitors[$visitor->getPriority()] = [];
-        }
-
         $this->visitors[$visitor->getPriority()][] = $visitor;
     }
 
diff --git a/src/Template.php b/src/Template.php
index 5919b74e5..c28f2b5a0 100644
--- a/src/Template.php
+++ b/src/Template.php
@@ -309,6 +309,15 @@ abstract class Template
                 return $template;
             }
 
+            if ($template === $this->getTemplateName()) {
+                $class = get_class($this);
+                if (false !== $pos = strrpos($class, '___', -1)) {
+                    $class = substr($class, 0, $pos);
+                }
+
+                return $this->env->loadClass($class, $template, $index);
+            }
+
             return $this->env->loadTemplate($template, $index);
         } catch (Error $e) {
             if (!$e->getSourceContext()) {
diff --git a/test/Twig/Tests/EnvironmentTest.php b/test/Twig/Tests/EnvironmentTest.php
index b76e8ecf8..ed36473a2 100644
--- a/test/Twig/Tests/EnvironmentTest.php
+++ b/test/Twig/Tests/EnvironmentTest.php
@@ -364,7 +364,7 @@ class Twig_Tests_EnvironmentTest extends \PHPUnit\Framework\TestCase
 
     /**
      * @expectedException \Twig\Error\RuntimeError
-     * @expectedExceptionMessage Failed to load Twig template "testFailLoadTemplate.twig", index "abc": cache is corrupted in "testFailLoadTemplate.twig".
+     * @expectedExceptionMessage Failed to load Twig template "testFailLoadTemplate.twig", index "abc": cache might be corrupted in "testFailLoadTemplate.twig".
      */
     public function testFailLoadTemplate()
     {
diff --git a/test/Twig/Tests/Fixtures/filters/batch_with_keys.test b/test/Twig/Tests/Fixtures/filters/batch_with_keys.test
index f3279a636..e56cd79bb 100644
--- a/test/Twig/Tests/Fixtures/filters/batch_with_keys.test
+++ b/test/Twig/Tests/Fixtures/filters/batch_with_keys.test
@@ -1,8 +1,8 @@
 --TEST--
 "batch" filter preserves array keys
 --TEMPLATE--
-{{ {'foo': 'bar', 'key': 'value'}|batch(4)|first|keys|join(',')  }}
-{{ {'foo': 'bar', 'key': 'value'}|batch(4, 'fill')|first|keys|join(',')  }}
+{{ {'foo': 'bar', 'key': 'value'}|batch(4)|first|keys|join(',') }}
+{{ {'foo': 'bar', 'key': 'value'}|batch(4, 'fill')|first|keys|join(',') }}
 --DATA--
 return []
 --EXPECT--
diff --git a/test/Twig/Tests/Fixtures/filters/batch_with_more_elements.test b/test/Twig/Tests/Fixtures/filters/batch_with_more_elements.test
new file mode 100644
index 000000000..90f4de685
--- /dev/null
+++ b/test/Twig/Tests/Fixtures/filters/batch_with_more_elements.test
@@ -0,0 +1,23 @@
+--TEST--
+"batch" filter
+--TEMPLATE--
+{% for row in items|batch(3, 'fill') %}
+  <div class=row>
+  {% for key, column in row %}
+    <div class={{ key }}>{{ column }}</div>
+  {% endfor %}
+  </div>
+{% endfor %}
+--DATA--
+return ['items' => ['a' => 'a', 'b' => 'b', 'c' => 'c', 'd' => 'd', '123' => 'e']]
+--EXPECT--
+<div class=row>
+      <div class=a>a</div>
+      <div class=b>b</div>
+      <div class=c>c</div>
+    </div>
+  <div class=row>
+      <div class=d>d</div>
+      <div class=123>e</div>
+      <div class=124>fill</div>
+    </div>
diff --git a/test/Twig/Tests/Fixtures/functions/include_template_from_string.test b/test/Twig/Tests/Fixtures/functions/include_template_from_string.test
new file mode 100644
index 000000000..8d9ba60ce
--- /dev/null
+++ b/test/Twig/Tests/Fixtures/functions/include_template_from_string.test
@@ -0,0 +1,11 @@
+--TEST--
+"template_from_string" function works in an "include"
+--TEMPLATE--
+{% set embed = '{% embed "embed.twig" %}{% endembed %}' %}
+{{ include(template_from_string(embed)) }}
+--TEMPLATE(embed.twig)--
+Cool
+--DATA--
+return []
+--EXPECT--
+Cool