From bd4d624cc7468623b29e56fa800b1750886b04c7 Mon Sep 17 00:00:00 2001
From: Jordi Boggiano <j.boggiano@seld.be>
Date: Tue, 9 Nov 2021 16:31:27 +0100
Subject: [PATCH] Read first from $_SERVER and $_ENV before using getenv
 (#10218)

---
 src/Composer/Cache.php                        |  3 +-
 src/Composer/Command/ConfigCommand.php        |  2 +-
 src/Composer/Command/GlobalCommand.php        |  2 +-
 src/Composer/Config.php                       |  6 ++--
 src/Composer/Console/Application.php          | 10 +++----
 src/Composer/Console/GithubActionError.php    |  3 +-
 src/Composer/Downloader/GitDownloader.php     |  4 +--
 src/Composer/Downloader/PathDownloader.php    |  2 +-
 .../EventDispatcher/EventDispatcher.php       | 17 ++++++-----
 src/Composer/Factory.php                      | 26 ++++++++--------
 .../Installer/InstallationManager.php         |  2 +-
 .../Package/Loader/RootPackageLoader.php      |  5 ++--
 src/Composer/Repository/PathRepository.php    |  2 +-
 src/Composer/Util/Git.php                     | 10 +++----
 src/Composer/Util/HttpDownloader.php          |  4 +--
 src/Composer/Util/Platform.php                | 30 +++++++++++++++----
 src/Composer/Util/StreamContextFactory.php    |  2 +-
 .../EventDispatcher/EventDispatcherTest.php   | 23 ++++++++------
 18 files changed, 90 insertions(+), 63 deletions(-)

diff --git a/src/Composer/Cache.php b/src/Composer/Cache.php
index b1baef8ea..6da4cb20a 100644
--- a/src/Composer/Cache.php
+++ b/src/Composer/Cache.php
@@ -14,6 +14,7 @@ namespace Composer;
 
 use Composer\IO\IOInterface;
 use Composer\Util\Filesystem;
+use Composer\Util\Platform;
 use Composer\Util\Silencer;
 use Symfony\Component\Finder\Finder;
 
@@ -242,7 +243,7 @@ class Cache
         }
 
         self::$cacheCollected = true;
-        if (getenv('COMPOSER_TEST_SUITE')) {
+        if (Platform::getEnv('COMPOSER_TEST_SUITE')) {
             return false;
         }
 
diff --git a/src/Composer/Command/ConfigCommand.php b/src/Composer/Command/ConfigCommand.php
index 4f486cc83..03ebd9682 100644
--- a/src/Composer/Command/ConfigCommand.php
+++ b/src/Composer/Command/ConfigCommand.php
@@ -213,7 +213,7 @@ EOT
     {
         // Open file in editor
         if ($input->getOption('editor')) {
-            $editor = escapeshellcmd(getenv('EDITOR'));
+            $editor = escapeshellcmd(Platform::getEnv('EDITOR'));
             if (!$editor) {
                 if (Platform::isWindows()) {
                     $editor = 'notepad';
diff --git a/src/Composer/Command/GlobalCommand.php b/src/Composer/Command/GlobalCommand.php
index 9fd711fe5..fbcb77eeb 100644
--- a/src/Composer/Command/GlobalCommand.php
+++ b/src/Composer/Command/GlobalCommand.php
@@ -88,7 +88,7 @@ EOT
         }
 
         // The COMPOSER env var should not apply to the global execution scope
-        if (getenv('COMPOSER')) {
+        if (Platform::getEnv('COMPOSER')) {
             Platform::clearEnv('COMPOSER');
         }
 
diff --git a/src/Composer/Config.php b/src/Composer/Config.php
index 5e0ab4bc0..0cbbf27dd 100644
--- a/src/Composer/Config.php
+++ b/src/Composer/Config.php
@@ -330,7 +330,7 @@ class Config
                 return (int) $this->config['cache-ttl'];
 
             case 'home':
-                $val = preg_replace('#^(\$HOME|~)(/|$)#', rtrim(getenv('HOME') ?: getenv('USERPROFILE'), '/\\') . '/', $this->config[$key]);
+                $val = preg_replace('#^(\$HOME|~)(/|$)#', rtrim(Platform::getEnv('HOME') ?: Platform::getEnv('USERPROFILE'), '/\\') . '/', $this->config[$key]);
 
                 return rtrim($this->process($val, $flags), '/\\');
 
@@ -462,7 +462,7 @@ class Config
             return $path;
         }
 
-        return $this->baseDir . '/' . $path;
+        return $this->baseDir ? $this->baseDir . '/' . $path : $path;
     }
 
     /**
@@ -477,7 +477,7 @@ class Config
     private function getComposerEnv($var)
     {
         if ($this->useEnvironment) {
-            return getenv($var);
+            return Platform::getEnv($var);
         }
 
         return false;
diff --git a/src/Composer/Console/Application.php b/src/Composer/Console/Application.php
index 7880d1471..e68321e29 100644
--- a/src/Composer/Console/Application.php
+++ b/src/Composer/Console/Application.php
@@ -135,7 +135,7 @@ class Application extends BaseApplication
     {
         $this->disablePluginsByDefault = $input->hasParameterOption('--no-plugins');
 
-        if (getenv('COMPOSER_NO_INTERACTION') || !Platform::isTty(defined('STDIN') ? STDIN : fopen('php://stdin', 'r'))) {
+        if (Platform::getEnv('COMPOSER_NO_INTERACTION') || !Platform::isTty(defined('STDIN') ? STDIN : fopen('php://stdin', 'r'))) {
             $input->setInteractive(false);
         }
 
@@ -174,7 +174,7 @@ class Application extends BaseApplication
         // prompt user for dir change if no composer.json is present in current dir
         if ($io->isInteractive() && !$newWorkDir && !in_array($commandName, array('', 'list', 'init', 'about', 'help', 'diagnose', 'self-update', 'global', 'create-project', 'outdated'), true) && !file_exists(Factory::getComposerFile())) {
             $dir = dirname(getcwd());
-            $home = realpath(getenv('HOME') ?: getenv('USERPROFILE') ?: '/');
+            $home = realpath(Platform::getEnv('HOME') ?: Platform::getEnv('USERPROFILE') ?: '/');
 
             // abort when we reach the home dir or top of the filesystem
             while (dirname($dir) !== $dir && $dir !== $home) {
@@ -253,7 +253,7 @@ class Application extends BaseApplication
                 $io->writeError('<warning>Composer only officially supports PHP 5.3.2 and above, you will most likely encounter problems with your PHP '.PHP_VERSION.', upgrading is strongly recommended.</warning>');
             }
 
-            if (XdebugHandler::isXdebugActive() && !getenv('COMPOSER_DISABLE_XDEBUG_WARN')) {
+            if (XdebugHandler::isXdebugActive() && !Platform::getEnv('COMPOSER_DISABLE_XDEBUG_WARN')) {
                 $io->writeError('<warning>Composer is operating slower than normal because you have Xdebug enabled. See https://getcomposer.org/xdebug</warning>');
             }
 
@@ -264,7 +264,7 @@ class Application extends BaseApplication
             if (
                 !Platform::isWindows()
                 && function_exists('exec')
-                && !getenv('COMPOSER_ALLOW_SUPERUSER')
+                && !Platform::getEnv('COMPOSER_ALLOW_SUPERUSER')
                 && (ini_get('open_basedir') || !file_exists('/.dockerenv'))
             ) {
                 if (function_exists('posix_getuid') && posix_getuid() === 0) {
@@ -277,7 +277,7 @@ class Application extends BaseApplication
                             }
                         }
                     }
-                    if ($uid = (int) getenv('SUDO_UID')) {
+                    if ($uid = (int) Platform::getEnv('SUDO_UID')) {
                         // Silently clobber any sudo credentials on the invoking user to avoid privilege escalations later on
                         // ref. https://github.com/composer/composer/issues/5119
                         Silencer::call('exec', "sudo -u \\#{$uid} sudo -K > /dev/null 2>&1");
diff --git a/src/Composer/Console/GithubActionError.php b/src/Composer/Console/GithubActionError.php
index 49048ffcf..9ccb8221d 100644
--- a/src/Composer/Console/GithubActionError.php
+++ b/src/Composer/Console/GithubActionError.php
@@ -13,6 +13,7 @@
 namespace Composer\Console;
 
 use Composer\IO\IOInterface;
+use Composer\Util\Platform;
 
 final class GithubActionError
 {
@@ -35,7 +36,7 @@ final class GithubActionError
      */
     public function emit($message, $file = null, $line = null)
     {
-        if (getenv('GITHUB_ACTIONS') && !getenv('COMPOSER_TESTS_ARE_RUNNING')) {
+        if (Platform::getEnv('GITHUB_ACTIONS') && !Platform::getEnv('COMPOSER_TESTS_ARE_RUNNING')) {
             $message = $this->escapeData($message);
 
             if ($file && $line) {
diff --git a/src/Composer/Downloader/GitDownloader.php b/src/Composer/Downloader/GitDownloader.php
index 3a9e94427..fc7f03066 100644
--- a/src/Composer/Downloader/GitDownloader.php
+++ b/src/Composer/Downloader/GitDownloader.php
@@ -99,7 +99,7 @@ class GitDownloader extends VcsDownloader implements DvcsDownloaderInterface
         } else {
             $msg = "Cloning ".$this->getShortHash($ref);
             $command = 'git clone --no-checkout -- %url% %path% && cd '.$flag.'%path% && git remote add composer -- %url% && git fetch composer && git remote set-url origin -- %sanitizedUrl% && git remote set-url composer -- %sanitizedUrl%';
-            if (getenv('COMPOSER_DISABLE_NETWORK')) {
+            if (Platform::getEnv('COMPOSER_DISABLE_NETWORK')) {
                 throw new \RuntimeException('The required git reference for '.$package->getName().' is not in cache and network is disabled, aborting');
             }
         }
@@ -157,7 +157,7 @@ class GitDownloader extends VcsDownloader implements DvcsDownloaderInterface
         } else {
             $msg = "Checking out ".$this->getShortHash($ref);
             $command = '(git remote set-url composer -- %url% && git rev-parse --quiet --verify %ref% || (git fetch composer && git fetch --tags composer)) && git remote set-url composer -- %sanitizedUrl%';
-            if (getenv('COMPOSER_DISABLE_NETWORK')) {
+            if (Platform::getEnv('COMPOSER_DISABLE_NETWORK')) {
                 throw new \RuntimeException('The required git reference for '.$target->getName().' is not in cache and network is disabled, aborting');
             }
         }
diff --git a/src/Composer/Downloader/PathDownloader.php b/src/Composer/Downloader/PathDownloader.php
index ffaed5515..9f8c62da6 100644
--- a/src/Composer/Downloader/PathDownloader.php
+++ b/src/Composer/Downloader/PathDownloader.php
@@ -255,7 +255,7 @@ class PathDownloader extends FileDownloader implements VcsCapableDownloaderInter
         $currentStrategy = self::STRATEGY_SYMLINK;
         $allowedStrategies = array(self::STRATEGY_SYMLINK, self::STRATEGY_MIRROR);
 
-        $mirrorPathRepos = getenv('COMPOSER_MIRROR_PATH_REPOS');
+        $mirrorPathRepos = Platform::getEnv('COMPOSER_MIRROR_PATH_REPOS');
         if ($mirrorPathRepos) {
             $currentStrategy = self::STRATEGY_MIRROR;
         }
diff --git a/src/Composer/EventDispatcher/EventDispatcher.php b/src/Composer/EventDispatcher/EventDispatcher.php
index 06e30792c..629b0deed 100644
--- a/src/Composer/EventDispatcher/EventDispatcher.php
+++ b/src/Composer/EventDispatcher/EventDispatcher.php
@@ -161,7 +161,7 @@ class EventDispatcher
      */
     protected function doDispatch(Event $event)
     {
-        if (getenv('COMPOSER_DEBUG_EVENTS')) {
+        if (Platform::getEnv('COMPOSER_DEBUG_EVENTS')) {
             $details = null;
             if ($event instanceof PackageEvent) {
                 $details = (string) $event->getOperation();
@@ -199,7 +199,7 @@ class EventDispatcher
                     $args = array_merge($script, $event->getArguments());
                     $flags = $event->getFlags();
                     if (strpos($callable, '@composer ') === 0) {
-                        $exec = $this->getPhpExecCommand() . ' ' . ProcessExecutor::escape(getenv('COMPOSER_BINARY')) . ' ' . implode(' ', $args);
+                        $exec = $this->getPhpExecCommand() . ' ' . ProcessExecutor::escape(Platform::getEnv('COMPOSER_BINARY')) . ' ' . implode(' ', $args);
                         if (0 !== ($exitCode = $this->executeTty($exec))) {
                             $this->io->writeError(sprintf('<error>Script %s handling the %s event returned with error code '.$exitCode.'</error>', $callable, $event->getName()), true, IOInterface::QUIET);
 
@@ -306,7 +306,7 @@ class EventDispatcher
                     // resolution, even if bin-dir contains composer too because the project requires composer/composer
                     // see https://github.com/composer/composer/issues/8748
                     if (strpos($exec, 'composer ') === 0) {
-                        $exec = $this->getPhpExecCommand() . ' ' . ProcessExecutor::escape(getenv('COMPOSER_BINARY')) . substr($exec, 8);
+                        $exec = $this->getPhpExecCommand() . ' ' . ProcessExecutor::escape(Platform::getEnv('COMPOSER_BINARY')) . substr($exec, 8);
                     }
 
                     if (0 !== ($exitCode = $this->executeTty($exec))) {
@@ -565,17 +565,18 @@ class EventDispatcher
      */
     private function ensureBinDirIsInPath()
     {
-        $pathStr = 'PATH';
-        if (!isset($_SERVER[$pathStr]) && isset($_SERVER['Path'])) {
-            $pathStr = 'Path';
+        $pathEnv = 'PATH';
+        if (false === Platform::getEnv('PATH') && false !== Platform::getEnv('Path')) {
+            $pathEnv = 'Path';
         }
 
         // add the bin dir to the PATH to make local binaries of deps usable in scripts
         $binDir = $this->composer->getConfig()->get('bin-dir');
         if (is_dir($binDir)) {
             $binDir = realpath($binDir);
-            if (isset($_SERVER[$pathStr]) && !preg_match('{(^|'.PATH_SEPARATOR.')'.preg_quote($binDir).'($|'.PATH_SEPARATOR.')}', $_SERVER[$pathStr])) {
-                Platform::putEnv($pathStr, $binDir.PATH_SEPARATOR.getenv($pathStr));
+            $pathValue = Platform::getEnv($pathEnv);
+            if (!preg_match('{(^|'.PATH_SEPARATOR.')'.preg_quote($binDir).'($|'.PATH_SEPARATOR.')}', $pathValue)) {
+                Platform::putEnv($pathEnv, $binDir.PATH_SEPARATOR.$pathValue);
             }
         }
     }
diff --git a/src/Composer/Factory.php b/src/Composer/Factory.php
index 7d08ec4d5..fdcee9034 100644
--- a/src/Composer/Factory.php
+++ b/src/Composer/Factory.php
@@ -56,17 +56,17 @@ class Factory
      */
     protected static function getHomeDir()
     {
-        $home = getenv('COMPOSER_HOME');
+        $home = Platform::getEnv('COMPOSER_HOME');
         if ($home) {
             return $home;
         }
 
         if (Platform::isWindows()) {
-            if (!getenv('APPDATA')) {
+            if (!Platform::getEnv('APPDATA')) {
                 throw new \RuntimeException('The APPDATA or COMPOSER_HOME environment variable must be set for composer to run correctly');
             }
 
-            return rtrim(strtr(getenv('APPDATA'), '\\', '/'), '/') . '/Composer';
+            return rtrim(strtr(Platform::getEnv('APPDATA'), '\\', '/'), '/') . '/Composer';
         }
 
         $userDir = self::getUserDir();
@@ -74,7 +74,7 @@ class Factory
 
         if (self::useXdg()) {
             // XDG Base Directory Specifications
-            $xdgConfig = getenv('XDG_CONFIG_HOME');
+            $xdgConfig = Platform::getEnv('XDG_CONFIG_HOME');
             if (!$xdgConfig) {
                 $xdgConfig = $userDir . '/.config';
             }
@@ -101,18 +101,18 @@ class Factory
      */
     protected static function getCacheDir($home)
     {
-        $cacheDir = getenv('COMPOSER_CACHE_DIR');
+        $cacheDir = Platform::getEnv('COMPOSER_CACHE_DIR');
         if ($cacheDir) {
             return $cacheDir;
         }
 
-        $homeEnv = getenv('COMPOSER_HOME');
+        $homeEnv = Platform::getEnv('COMPOSER_HOME');
         if ($homeEnv) {
             return $homeEnv . '/cache';
         }
 
         if (Platform::isWindows()) {
-            if ($cacheDir = getenv('LOCALAPPDATA')) {
+            if ($cacheDir = Platform::getEnv('LOCALAPPDATA')) {
                 $cacheDir .= '/Composer';
             } else {
                 $cacheDir = $home . '/cache';
@@ -136,7 +136,7 @@ class Factory
         }
 
         if (self::useXdg()) {
-            $xdgCache = getenv('XDG_CACHE_HOME') ?: $userDir . '/.cache';
+            $xdgCache = Platform::getEnv('XDG_CACHE_HOME') ?: $userDir . '/.cache';
 
             return $xdgCache . '/composer';
         }
@@ -150,7 +150,7 @@ class Factory
      */
     protected static function getDataDir($home)
     {
-        $homeEnv = getenv('COMPOSER_HOME');
+        $homeEnv = Platform::getEnv('COMPOSER_HOME');
         if ($homeEnv) {
             return $homeEnv;
         }
@@ -161,7 +161,7 @@ class Factory
 
         $userDir = self::getUserDir();
         if ($home !== $userDir . '/.composer' && self::useXdg()) {
-            $xdgData = getenv('XDG_DATA_HOME') ?: $userDir . '/.local/share';
+            $xdgData = Platform::getEnv('XDG_DATA_HOME') ?: $userDir . '/.local/share';
 
             return $xdgData . '/composer';
         }
@@ -225,7 +225,7 @@ class Factory
         $config->setAuthConfigSource(new JsonConfigSource($file, true));
 
         // load COMPOSER_AUTH environment variable if set
-        if ($composerAuthEnv = getenv('COMPOSER_AUTH')) {
+        if ($composerAuthEnv = Platform::getEnv('COMPOSER_AUTH')) {
             $authData = json_decode($composerAuthEnv, true);
 
             if (null === $authData) {
@@ -248,7 +248,7 @@ class Factory
      */
     public static function getComposerFile()
     {
-        return trim(getenv('COMPOSER')) ?: './composer.json';
+        return trim(Platform::getEnv('COMPOSER')) ?: './composer.json';
     }
 
     /**
@@ -713,7 +713,7 @@ class Factory
      */
     private static function getUserDir()
     {
-        $home = getenv('HOME');
+        $home = Platform::getEnv('HOME');
         if (!$home) {
             throw new \RuntimeException('The HOME or COMPOSER_HOME environment variable must be set for composer to run correctly');
         }
diff --git a/src/Composer/Installer/InstallationManager.php b/src/Composer/Installer/InstallationManager.php
index 6429e1b56..07e6709c7 100644
--- a/src/Composer/Installer/InstallationManager.php
+++ b/src/Composer/Installer/InstallationManager.php
@@ -488,7 +488,7 @@ class InstallationManager
         if (
             $this->outputProgress
             && $this->io instanceof ConsoleIO
-            && !getenv('CI')
+            && !Platform::getEnv('CI')
             && !$this->io->isDebug()
             && count($promises) > 1
         ) {
diff --git a/src/Composer/Package/Loader/RootPackageLoader.php b/src/Composer/Package/Loader/RootPackageLoader.php
index ed9a4a88c..ce4601756 100644
--- a/src/Composer/Package/Loader/RootPackageLoader.php
+++ b/src/Composer/Package/Loader/RootPackageLoader.php
@@ -21,6 +21,7 @@ use Composer\Package\Version\VersionGuesser;
 use Composer\Package\Version\VersionParser;
 use Composer\Package\RootPackage;
 use Composer\Repository\RepositoryManager;
+use Composer\Util\Platform;
 use Composer\Util\ProcessExecutor;
 
 /**
@@ -83,8 +84,8 @@ class RootPackageLoader extends ArrayLoader
             $commit = null;
 
             // override with env var if available
-            if (getenv('COMPOSER_ROOT_VERSION')) {
-                $config['version'] = getenv('COMPOSER_ROOT_VERSION');
+            if (Platform::getEnv('COMPOSER_ROOT_VERSION')) {
+                $config['version'] = Platform::getEnv('COMPOSER_ROOT_VERSION');
             } else {
                 $versionData = $this->versionGuesser->guessVersion($config, $cwd ?: getcwd());
                 if ($versionData) {
diff --git a/src/Composer/Repository/PathRepository.php b/src/Composer/Repository/PathRepository.php
index afdf84749..630413d36 100644
--- a/src/Composer/Repository/PathRepository.php
+++ b/src/Composer/Repository/PathRepository.php
@@ -179,7 +179,7 @@ class PathRepository extends ArrayRepository implements ConfigurableRepositoryIn
             }
 
             // carry over the root package version if this path repo is in the same git repository as root package
-            if (!isset($package['version']) && ($rootVersion = getenv('COMPOSER_ROOT_VERSION'))) {
+            if (!isset($package['version']) && ($rootVersion = Platform::getEnv('COMPOSER_ROOT_VERSION'))) {
                 if (
                     0 === $this->process->execute('git rev-parse HEAD', $ref1, $path)
                     && 0 === $this->process->execute('git rev-parse HEAD', $ref2)
diff --git a/src/Composer/Util/Git.php b/src/Composer/Util/Git.php
index a350629db..f3ebd1301 100644
--- a/src/Composer/Util/Git.php
+++ b/src/Composer/Util/Git.php
@@ -273,7 +273,7 @@ class Git
      */
     public function syncMirror($url, $dir)
     {
-        if (getenv('COMPOSER_DISABLE_NETWORK') && getenv('COMPOSER_DISABLE_NETWORK') !== 'prime') {
+        if (Platform::getEnv('COMPOSER_DISABLE_NETWORK') && Platform::getEnv('COMPOSER_DISABLE_NETWORK') !== 'prime') {
             $this->io->writeError('<warning>Aborting git mirror sync of '.$url.' as network is disabled</warning>');
 
             return false;
@@ -401,20 +401,20 @@ class Git
         }
 
         // added in git 1.7.1, prevents prompting the user for username/password
-        if (getenv('GIT_ASKPASS') !== 'echo') {
+        if (Platform::getEnv('GIT_ASKPASS') !== 'echo') {
             Platform::putEnv('GIT_ASKPASS', 'echo');
         }
 
         // clean up rogue git env vars in case this is running in a git hook
-        if (getenv('GIT_DIR')) {
+        if (Platform::getEnv('GIT_DIR')) {
             Platform::clearEnv('GIT_DIR');
         }
-        if (getenv('GIT_WORK_TREE')) {
+        if (Platform::getEnv('GIT_WORK_TREE')) {
             Platform::clearEnv('GIT_WORK_TREE');
         }
 
         // Run processes with predictable LANGUAGE
-        if (getenv('LANGUAGE') !== 'C') {
+        if (Platform::getEnv('LANGUAGE') !== 'C') {
             Platform::putEnv('LANGUAGE', 'C');
         }
 
diff --git a/src/Composer/Util/HttpDownloader.php b/src/Composer/Util/HttpDownloader.php
index 1706dab9f..59715ea29 100644
--- a/src/Composer/Util/HttpDownloader.php
+++ b/src/Composer/Util/HttpDownloader.php
@@ -70,7 +70,7 @@ class HttpDownloader
     {
         $this->io = $io;
 
-        $this->disabled = (bool) getenv('COMPOSER_DISABLE_NETWORK');
+        $this->disabled = (bool) Platform::getEnv('COMPOSER_DISABLE_NETWORK');
 
         // Setup TLS options
         // The cafile option can be set via config.json
@@ -88,7 +88,7 @@ class HttpDownloader
 
         $this->rfs = new RemoteFilesystem($io, $config, $options, $disableTls);
 
-        if (is_numeric($maxJobs = getenv('COMPOSER_MAX_PARALLEL_HTTP'))) {
+        if (is_numeric($maxJobs = Platform::getEnv('COMPOSER_MAX_PARALLEL_HTTP'))) {
             $this->maxJobs = max(1, min(50, (int) $maxJobs));
         }
     }
diff --git a/src/Composer/Util/Platform.php b/src/Composer/Util/Platform.php
index 8f8ed2682..3098a4aa3 100644
--- a/src/Composer/Util/Platform.php
+++ b/src/Composer/Util/Platform.php
@@ -24,6 +24,24 @@ class Platform
     /** @var ?bool */
     private static $isWindowsSubsystemForLinux = null;
 
+    /**
+     * getenv() equivalent but reads from the runtime global variables first
+     *
+     * @param  string $name
+     * @return string|false
+     */
+    public static function getEnv($name)
+    {
+        if (array_key_exists($name, $_SERVER)) {
+            return (string) $_SERVER[$name];
+        }
+        if (array_key_exists($name, $_ENV)) {
+            return (string) $_ENV[$name];
+        }
+
+        return getenv($name);
+    }
+
     /**
      * putenv() equivalent but updates the runtime global variables too
      *
@@ -65,10 +83,10 @@ class Platform
         return preg_replace_callback('#^(\$|(?P<percent>%))(?P<var>\w++)(?(percent)%)(?P<path>.*)#', function ($matches) {
             // Treat HOME as an alias for USERPROFILE on Windows for legacy reasons
             if (Platform::isWindows() && $matches['var'] == 'HOME') {
-                return (getenv('HOME') ?: getenv('USERPROFILE')) . $matches['path'];
+                return (Platform::getEnv('HOME') ?: Platform::getEnv('USERPROFILE')) . $matches['path'];
             }
 
-            return getenv($matches['var']) . $matches['path'];
+            return Platform::getEnv($matches['var']) . $matches['path'];
         }, $path);
     }
 
@@ -78,11 +96,11 @@ class Platform
      */
     public static function getUserDirectory()
     {
-        if (false !== ($home = getenv('HOME'))) {
+        if (false !== ($home = self::getEnv('HOME'))) {
             return $home;
         }
 
-        if (self::isWindows() && false !== ($home = getenv('USERPROFILE'))) {
+        if (self::isWindows() && false !== ($home = self::getEnv('USERPROFILE'))) {
             return $home;
         }
 
@@ -159,7 +177,7 @@ class Platform
 
         // detect msysgit/mingw and assume this is a tty because detection
         // does not work correctly, see https://github.com/composer/composer/issues/9690
-        if (in_array(strtoupper(getenv('MSYSTEM') ?: ''), array('MINGW32', 'MINGW64'), true)) {
+        if (in_array(strtoupper(self::getEnv('MSYSTEM') ?: ''), array('MINGW32', 'MINGW64'), true)) {
             return true;
         }
 
@@ -211,7 +229,7 @@ class Platform
                 }
             }
 
-            if (getenv('COMPOSER_RUNTIME_ENV') === 'virtualbox') {
+            if (self::getEnv('COMPOSER_RUNTIME_ENV') === 'virtualbox') {
                 return self::$isVirtualBoxGuest = true;
             }
 
diff --git a/src/Composer/Util/StreamContextFactory.php b/src/Composer/Util/StreamContextFactory.php
index 9cab3b2fe..c63c6118d 100644
--- a/src/Composer/Util/StreamContextFactory.php
+++ b/src/Composer/Util/StreamContextFactory.php
@@ -122,7 +122,7 @@ final class StreamContextFactory
                 $phpVersion,
                 $httpVersion,
                 $platformPhpVersion ? '; Platform-PHP '.$platformPhpVersion : '',
-                getenv('CI') ? '; CI' : ''
+                Platform::getEnv('CI') ? '; CI' : ''
             );
         }
 
diff --git a/tests/Composer/Test/EventDispatcher/EventDispatcherTest.php b/tests/Composer/Test/EventDispatcher/EventDispatcherTest.php
index 8e5184564..4bde2c2ab 100644
--- a/tests/Composer/Test/EventDispatcher/EventDispatcherTest.php
+++ b/tests/Composer/Test/EventDispatcher/EventDispatcherTest.php
@@ -24,6 +24,7 @@ use Composer\Script\ScriptEvents;
 use Composer\Script\Event as ScriptEvent;
 use Composer\Util\ProcessExecutor;
 use Composer\Test\Mock\ProcessExecutorMock;
+use Composer\Util\Platform;
 use Symfony\Component\Console\Output\OutputInterface;
 
 class EventDispatcherTest extends TestCase
@@ -294,9 +295,9 @@ class EventDispatcherTest extends TestCase
     public function testDispatcherAppendsDirBinOnPathForEveryListener()
     {
         $currentDirectoryBkp = getcwd();
-        $composerBinDirBkp = getenv('COMPOSER_BIN_DIR');
+        $composerBinDirBkp = Platform::getEnv('COMPOSER_BIN_DIR');
         chdir(__DIR__);
-        putenv('COMPOSER_BIN_DIR=' . __DIR__ . sprintf('%svendor%sbin', DIRECTORY_SEPARATOR, DIRECTORY_SEPARATOR));
+        Platform::putEnv('COMPOSER_BIN_DIR', __DIR__ . '/vendor/bin');
 
         $dispatcher = $this->getMockBuilder('Composer\EventDispatcher\EventDispatcher')->setConstructorArgs(array(
                 $this->createComposerInstance(),
@@ -314,11 +315,15 @@ class EventDispatcherTest extends TestCase
         $dispatcher->expects($this->atLeastOnce())->method('getListeners')->will($this->returnValue($listeners));
 
         $dispatcher->dispatchScript(ScriptEvents::POST_INSTALL_CMD, false);
-        rmdir(__DIR__ . sprintf('%svendor%sbin', DIRECTORY_SEPARATOR, DIRECTORY_SEPARATOR));
-        rmdir(__DIR__ . sprintf('%svendor', DIRECTORY_SEPARATOR));
+        rmdir(__DIR__ . '/vendor/bin');
+        rmdir(__DIR__ . '/vendor');
 
         chdir($currentDirectoryBkp);
-        putenv('COMPOSER_BIN_DIR' . ($composerBinDirBkp === false ? '' : '=' . $composerBinDirBkp));
+        if ($composerBinDirBkp) {
+            Platform::putEnv('COMPOSER_BIN_DIR', $composerBinDirBkp);
+        } else {
+            Platform::clearEnv('COMPOSER_BIN_DIR');
+        }
     }
 
     /**
@@ -326,14 +331,14 @@ class EventDispatcherTest extends TestCase
      */
     public static function createsVendorBinFolderChecksEnvDoesNotContainsBin()
     {
-        mkdir(__DIR__ . sprintf('%svendor%sbin', DIRECTORY_SEPARATOR, DIRECTORY_SEPARATOR), 0700, true);
+        mkdir(__DIR__ . '/vendor/bin', 0700, true);
         $val = getenv('PATH');
 
         if (!$val) {
             $val = getenv('Path');
         }
 
-        self::assertFalse(strpos($val, __DIR__ . sprintf('%svendor%sbin', DIRECTORY_SEPARATOR, DIRECTORY_SEPARATOR)));
+        self::assertStringNotContainsString(__DIR__ . DIRECTORY_SEPARATOR . 'vendor' . DIRECTORY_SEPARATOR . 'bin', $val);
     }
 
     /**
@@ -347,7 +352,7 @@ class EventDispatcherTest extends TestCase
             $val = getenv('Path');
         }
 
-        self::assertNotFalse(strpos($val, __DIR__ . sprintf('%svendor%sbin', DIRECTORY_SEPARATOR, DIRECTORY_SEPARATOR)));
+        self::assertStringContainsString(__DIR__ . DIRECTORY_SEPARATOR . 'vendor' . DIRECTORY_SEPARATOR . 'bin', $val);
     }
 
     /**
@@ -628,7 +633,7 @@ class EventDispatcherTest extends TestCase
     private function createComposerInstance()
     {
         $composer = new Composer;
-        $config = new Config;
+        $config = new Config();
         $composer->setConfig($config);
         $package = $this->getMockBuilder('Composer\Package\RootPackageInterface')->getMock();
         $composer->setPackage($package);