diff --git a/src/Composer/Command/ArchiveCommand.php b/src/Composer/Command/ArchiveCommand.php
index bf64ca47e..4ab1e4905 100644
--- a/src/Composer/Command/ArchiveCommand.php
+++ b/src/Composer/Command/ArchiveCommand.php
@@ -66,8 +66,9 @@ EOT
         $composer = $this->getComposer(false);
         if ($composer) {
             $commandEvent = new CommandEvent(PluginEvents::COMMAND, 'archive', $input, $output);
-            $composer->getEventDispatcher()->dispatch($commandEvent->getName(), $commandEvent);
-            $composer->getEventDispatcher()->dispatchScript(ScriptEvents::PRE_ARCHIVE_CMD);
+            $eventDispatcher = $composer->getEventDispatcher();
+            $eventDispatcher->dispatch($commandEvent->getName(), $commandEvent);
+            $eventDispatcher->dispatchScript(ScriptEvents::PRE_ARCHIVE_CMD);
         }
 
         if (null === $input->getOption('format')) {
diff --git a/src/Composer/Command/BaseDependencyCommand.php b/src/Composer/Command/BaseDependencyCommand.php
index e36663558..980ca9282 100644
--- a/src/Composer/Command/BaseDependencyCommand.php
+++ b/src/Composer/Command/BaseDependencyCommand.php
@@ -180,8 +180,9 @@ class BaseDependencyCommand extends BaseCommand
         // Render table
         $renderer = new Table($output);
         $renderer->setStyle('compact');
-        $renderer->getStyle()->setVerticalBorderChar('');
-        $renderer->getStyle()->setCellRowContentFormat('%s  ');
+        $rendererStyle = $renderer->getStyle();
+        $rendererStyle->setVerticalBorderChar('');
+        $rendererStyle->setCellRowContentFormat('%s  ');
         $renderer->setRows($table)->render();
     }
 
diff --git a/src/Composer/Command/CheckPlatformReqsCommand.php b/src/Composer/Command/CheckPlatformReqsCommand.php
index 8b59c28ea..6a75ab4dc 100644
--- a/src/Composer/Command/CheckPlatformReqsCommand.php
+++ b/src/Composer/Command/CheckPlatformReqsCommand.php
@@ -142,8 +142,9 @@ EOT
         // Render table
         $renderer = new Table($output);
         $renderer->setStyle('compact');
-        $renderer->getStyle()->setVerticalBorderChar('');
-        $renderer->getStyle()->setCellRowContentFormat('%s  ');
+        $rendererStyle = $renderer->getStyle();
+        $rendererStyle->setVerticalBorderChar('');
+        $rendererStyle->setCellRowContentFormat('%s  ');
         $renderer->setRows($table)->render();
     }
 }
diff --git a/src/Composer/Command/LicensesCommand.php b/src/Composer/Command/LicensesCommand.php
index 0c4537be1..f3a71eb39 100644
--- a/src/Composer/Command/LicensesCommand.php
+++ b/src/Composer/Command/LicensesCommand.php
@@ -74,8 +74,9 @@ EOT
 
                 $table = new Table($output);
                 $table->setStyle('compact');
-                $table->getStyle()->setVerticalBorderChar('');
-                $table->getStyle()->setCellRowContentFormat('%s  ');
+                $tableStyle = $table->getStyle();
+                $tableStyle->setVerticalBorderChar('');
+                $tableStyle->setCellRowContentFormat('%s  ');
                 $table->setHeaders(array('Name', 'Version', 'License'));
                 foreach ($packages as $package) {
                     $table->addRow(array(
diff --git a/src/Composer/Command/RunScriptCommand.php b/src/Composer/Command/RunScriptCommand.php
index d78662e23..ff0c79361 100644
--- a/src/Composer/Command/RunScriptCommand.php
+++ b/src/Composer/Command/RunScriptCommand.php
@@ -124,8 +124,9 @@ EOT
 
         $renderer = new Table($output);
         $renderer->setStyle('compact');
-        $renderer->getStyle()->setVerticalBorderChar('');
-        $renderer->getStyle()->setCellRowContentFormat('%s  ');
+        $rendererStyle = $renderer->getStyle();
+        $rendererStyle->setVerticalBorderChar('');
+        $rendererStyle->setCellRowContentFormat('%s  ');
         $renderer->setRows($table)->render();
 
         return 0;
diff --git a/src/Composer/Util/StreamContextFactory.php b/src/Composer/Util/StreamContextFactory.php
index b8290086c..6b16c8a18 100644
--- a/src/Composer/Util/StreamContextFactory.php
+++ b/src/Composer/Util/StreamContextFactory.php
@@ -169,7 +169,7 @@ final class StreamContextFactory
             $header = explode("\r\n", $header);
         }
         uasort($header, function ($el) {
-            return preg_match('{^content-type}i', $el) ? 1 : -1;
+            return stripos($el, 'content-type') === 0 ? 1 : -1;
         });
 
         return $header;
diff --git a/tests/Composer/Test/Util/FilesystemTest.php b/tests/Composer/Test/Util/FilesystemTest.php
index ef3ab5bbe..5a9adbae7 100644
--- a/tests/Composer/Test/Util/FilesystemTest.php
+++ b/tests/Composer/Test/Util/FilesystemTest.php
@@ -307,9 +307,9 @@ class FilesystemTest extends TestCase
         $this->assertTrue($fs->isJunction($junction . '/../junction'));
 
         // Remove junction
-        $this->assertTrue(is_dir($junction));
+        $this->assertDirectoryExists($junction);
         $this->assertTrue($fs->removeJunction($junction));
-        $this->assertFalse(is_dir($junction));
+        $this->assertDirectoryNotExists($junction);
     }
 
     public function testCopy()
@@ -325,9 +325,9 @@ class FilesystemTest extends TestCase
 
         $result1 = $fs->copy($this->workingDir . '/foo', $this->workingDir . '/foop');
         $this->assertTrue($result1, 'Copying directory failed.');
-        $this->assertTrue(is_dir($this->workingDir . '/foop'), 'Not a directory: ' . $this->workingDir . '/foop');
-        $this->assertTrue(is_dir($this->workingDir . '/foop/bar'), 'Not a directory: ' . $this->workingDir . '/foop/bar');
-        $this->assertTrue(is_dir($this->workingDir . '/foop/baz'), 'Not a directory: ' . $this->workingDir . '/foop/baz');
+        $this->assertDirectoryExists($this->workingDir . '/foop', 'Not a directory: ' . $this->workingDir . '/foop');
+        $this->assertDirectoryExists($this->workingDir . '/foop/bar', 'Not a directory: ' . $this->workingDir . '/foop/bar');
+        $this->assertDirectoryExists($this->workingDir . '/foop/baz', 'Not a directory: ' . $this->workingDir . '/foop/baz');
         $this->assertTrue(is_file($this->workingDir . '/foop/foo.file'), 'Not a file: ' . $this->workingDir . '/foop/foo.file');
         $this->assertTrue(is_file($this->workingDir . '/foop/bar/foobar.file'), 'Not a file: ' . $this->workingDir . '/foop/bar/foobar.file');
         $this->assertTrue(is_file($this->workingDir . '/foop/baz/foobaz.file'), 'Not a file: ' . $this->workingDir . '/foop/baz/foobaz.file');
@@ -355,8 +355,8 @@ class FilesystemTest extends TestCase
         $this->assertFalse(is_file($this->workingDir . '/foo/baz/foobaz.file'), 'Still a file: ' . $this->workingDir . '/foo/baz/foobaz.file');
         $this->assertFalse(is_file($this->workingDir . '/foo/bar/foobar.file'), 'Still a file: ' . $this->workingDir . '/foo/bar/foobar.file');
         $this->assertFalse(is_file($this->workingDir . '/foo/foo.file'), 'Still a file: ' . $this->workingDir . '/foo/foo.file');
-        $this->assertFalse(is_dir($this->workingDir . '/foo/baz'), 'Still a directory: ' . $this->workingDir . '/foo/baz');
-        $this->assertFalse(is_dir($this->workingDir . '/foo/bar'), 'Still a directory: ' . $this->workingDir . '/foo/bar');
-        $this->assertFalse(is_dir($this->workingDir . '/foo'), 'Still a directory: ' . $this->workingDir . '/foo');
+        $this->assertDirectoryNotExists($this->workingDir . '/foo/baz', 'Still a directory: ' . $this->workingDir . '/foo/baz');
+        $this->assertDirectoryNotExists($this->workingDir . '/foo/bar', 'Still a directory: ' . $this->workingDir . '/foo/bar');
+        $this->assertDirectoryNotExists($this->workingDir . '/foo', 'Still a directory: ' . $this->workingDir . '/foo');
     }
 }