[Locale] fixed StubIntlDateFormatter to behave like the ext/intl implementation

src/Symfony/Component/Locale/Stub/StubIntlDateFormatter.php

@@ -458,7 +458,12 @@ class StubIntlDateFormatter
     public function setTimeZoneId($timeZoneId)
     {
         if (null === $timeZoneId) {
-            $timeZoneId = date_default_timezone_get();
+            // TODO: changes were made to ext/intl in PHP 5.4.4 release that need to be investigated since it will
+            // use ini's date.timezone when the time zone is not provided. As a not well tested workaround, uses UTC.
+            // See the first two items of the commit message for more information:
+            // https://github.com/php/php-src/commit/eb346ef0f419b90739aadfb6cc7b7436c5b521d9
+            $timeZoneId = getenv('TZ') ?: 'UTC';
+
             $this->unitializedTimeZoneId = true;
         }
 

tests/Symfony/Tests/Component/Locale/Stub/StubIntlDateFormatterTest.php

@@ -463,13 +463,62 @@ class StubIntlDateFormatterTest extends LocaleTestCase
     {
         $this->skipIfIntlExtensionIsNotLoaded();
         $this->skipIfICUVersionIsTooOld();
+
+        $formatter = new \IntlDateFormatter('en', StubIntlDateFormatter::MEDIUM, StubIntlDateFormatter::SHORT);
+        $formatter->setPattern('yyyy-MM-dd HH:mm:ss');
+
+        $this->assertEquals(
+            $this->createDateTime(0)->format('Y-m-d H:i:s'),
+            $formatter->format(0)
+        );
+    }
+
+    public function testFormatWithDefaultTimezoneStubShouldUseTheTzEnvironmentVariableWhenAvailable()
+    {
+        $tz = getenv('TZ');
+        putenv('TZ=Europe/London');
+
+        $formatter = new StubIntlDateFormatter('en', StubIntlDateFormatter::MEDIUM, StubIntlDateFormatter::SHORT);
+        $formatter->setPattern('yyyy-MM-dd HH:mm:ss');
+
+        $this->assertEquals(
+            $this->createDateTime(0)->format('Y-m-d H:i:s'),
+            $formatter->format(0)
+        );
+
+        $this->assertEquals('Europe/London', getenv('TZ'));
+
+        // Restores TZ.
+        putenv('TZ='.$tz);
+    }
+
+    /**
+     * It seems IntlDateFormatter caches the timezone id when not explicitely set via constructor or by the
+     * setTimeZoneId() method. Since testFormatWithDefaultTimezoneIntl() runs using the default environment
+     * time zone, this test would use it too if not running in a separated process.
+     *
+     * @runInSeparateProcess
+     */
+    public function testFormatWithDefaultTimezoneIntlShouldUseTheTzEnvironmentVariableWhenAvailable()
+    {
+        $this->skipIfIntlExtensionIsNotLoaded();
+        $this->skipIfICUVersionIsTooOld();
+
+        $tz = getenv('TZ');
+        putenv('TZ=Europe/Paris');
+
         $formatter = new \IntlDateFormatter('en', StubIntlDateFormatter::MEDIUM, StubIntlDateFormatter::SHORT);
         $formatter->setPattern('yyyy-MM-dd HH:mm:ss');
 
+        $this->assertEquals('Europe/Paris', getenv('TZ'));
+
         $this->assertEquals(
             $this->createDateTime(0)->format('Y-m-d H:i:s'),
             $formatter->format(0)
         );
+
+        // Restores TZ.
+        putenv('TZ='.$tz);
     }
 
     /**
@@ -994,11 +1043,13 @@ class StubIntlDateFormatterTest extends LocaleTestCase
         return new \IntlDateFormatter('en', \IntlDateFormatter::MEDIUM, \IntlDateFormatter::SHORT, 'UTC', \IntlDateFormatter::GREGORIAN, $pattern);
     }
 
-    protected function createDateTime($timestamp = null, $timeZone = null)
+    protected function createDateTime($timestamp = null)
     {
+        $timeZone = getenv('TZ') ?: 'UTC';
+
         $dateTime = new \DateTime();
         $dateTime->setTimestamp(null === $timestamp ? time() : $timestamp);
-        $dateTime->setTimeZone(new \DateTimeZone(null === $timeZone ? date_default_timezone_get() : $timeZone));
+        $dateTime->setTimeZone(new \DateTimeZone($timeZone));
 
         return $dateTime;
     }