Added test for #1775

/cc @CameronHall, @niden

CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
   [#1779](https://github.com/phalcon/zephir/issues/1779)
 - Use namespace as a prefix for ini name [#1604](https://github.com/phalcon/zephir/issues/1604)
 - Fixed calling anonymous functions by resolving context [#1751](https://github.com/phalcon/zephir/issues/1751)
+- Fixed a bug when accessing super-global variables that do not exist [#1775](https://github.com/phalcon/zephir/issues/1775)
 
 ## [0.11.9] - 2019-01-15
 - Fixed `zend_closure` declaration to reflect PHP 7.3 changes

unit-tests/Extension/Globals/SessionTest.php

@@ -12,6 +12,7 @@
 namespace Extension\Globals;
 
 use PHPUnit\Framework\TestCase;
+use Test\Globals\Session\Base;
 use Test\Globals\Session\Child;
 
 class SessionTest extends TestCase
@@ -81,4 +82,21 @@ public function removeFromUnset()
 
         $this->assertSame([], $_SESSION);
     }
+
+    /**
+     * @test
+     * @see https://github.com/phalcon/zephir/issues/1775
+     */
+    public function shouldAccessToTheSession()
+    {
+        unset($_SESSION);
+        $this->assertFalse(isset($_SESSION));
+
+        $t = new Base();
+        $t->set('foo', 'bar');
+
+        $this->assertTrue(isset($_SESSION));
+        /** @noinspection PhpUndefinedVariableInspection */
+        $this->assertSame(['foo' => 'bar'], $_SESSION);
+    }
 }