Workaround for Dotenv and issues with concurrent requests failing (especially on Windows) because of PHP threaded getenv/putenv implementation. To make this really work, use `getEnvironmentVariable` instead of `getenv` everywhere (e.g. Laravel's `env()` helper, as in the patch https://gist.github.com/progmars/5c18235360c04b621ed7 ).

dotenv_2_mt_reliability_workaround_vendor.patch

This is a workaround patch for `getenv()` unstable behavior in multithreaded "PHP as Apache module" environments 
(e.g. some prepackaged WAMP stacks).
See
https://github.com/vlucas/phpdotenv/issues/76
https://github.com/vlucas/phpdotenv/issues/163
This fix is intended only for development environments, the same as Dotenv itself.
The paths are based on Composer's vendor directory. 
diff --git a/vendor/vlucas/phpdotenv/src/Dotenv.php b/vendor/vlucas/phpdotenv/src/Dotenv.php
index 0737a70..d734a8b 100644
--- a/vendor/vlucas/phpdotenv/src/Dotenv.php
+++ b/vendor/vlucas/phpdotenv/src/Dotenv.php
@@ -55,6 +55,16 @@ class Dotenv
     }
 
     /**
+     * Returns current loader.
+     *
+     * @return \Dotenv\Loader
+     */
+    public function getLoader()
+    {
+        return $this->loader;
+    }
+
+    /**
      * Returns the full path to the file.
      *
      * @param string $path
diff --git a/vendor/vlucas/phpdotenv/src/Loader.php b/vendor/vlucas/phpdotenv/src/Loader.php
index ec843e9..4964485 100644
--- a/vendor/vlucas/phpdotenv/src/Loader.php
+++ b/vendor/vlucas/phpdotenv/src/Loader.php
@@ -29,6 +29,14 @@ class Loader
     protected $immutable;
 
     /**
+     * Cache to work around issues of getenv() losing values
+     * in multithread configurations.
+     *
+     * @var array
+     */
+    protected $cache;
+
+    /**
      * Create a new loader instance.
      *
      * @param string $filePath
@@ -40,6 +48,7 @@ class Loader
     {
         $this->filePath = $filePath;
         $this->immutable = $immutable;
+        $this->cache = [];
     }
 
     /**
@@ -300,6 +309,9 @@ class Loader
     public function getEnvironmentVariable($name)
     {
         switch (true) {
+            // Patched to check the local cache first.
+            case array_key_exists($name, $this->cache):
+                return $this->cache[$name];
             case array_key_exists($name, $_ENV):
                 return $_ENV[$name];
             case array_key_exists($name, $_SERVER):
@@ -316,7 +328,8 @@ class Loader
      * This is done using:
      * - putenv,
      * - $_ENV,
-     * - $_SERVER.
+     * - $_SERVER
+     * and local cache to work around losing values in some environments.
      *
      * The environment variable value is stripped of single and double quotes.
      *
@@ -329,12 +342,30 @@ class Loader
     {
         list($name, $value) = $this->normaliseEnvironmentVariable($name, $value);
 
+        // Patched to support more reliable environment value lookup
+        // in some environments.
+        // See
+        // https://github.com/vlucas/phpdotenv/issues/76
+        // https://github.com/vlucas/phpdotenv/issues/163
+
+        $currentValue = $this->getEnvironmentVariable($name);
+
+        // If we got the value but didn't have it in our cache yet,
+        // then it was specified from outside (possibly leaked from another thread).
+        // Now let's propagate this behavior into Dotenv and sync the cache 
+        // with the current value for consistency.
+        if ($currentValue !== null && !array_key_exists($name, $this->cache)){
+            $this->cache[$name] = $currentValue;
+        }
+
         // Don't overwrite existing environment variables if we're immutable
         // Ruby's dotenv does this with `ENV[key] ||= value`.
-        if ($this->immutable && $this->getEnvironmentVariable($name) !== null) {
+        if ($this->immutable && $currentValue !== null) {
             return;
         }
 
+        $this->cache[$name] = $value;
+
         putenv("$name=$value");
 
         $_ENV[$name] = $value;
@@ -349,7 +380,7 @@ class Loader
      *
      * This is done using:
      * - putenv,
-     * - unset($_ENV, $_SERVER).
+     * - unset($_ENV, $_SERVER, $this->cache).
      *
      * @param string $name
      *
@@ -366,6 +397,7 @@ class Loader
 
         putenv($name);
 
-        unset($_ENV[$name], $_SERVER[$name]);
+        // Patched to clear everything, including the cache
+        unset($_ENV[$name], $_SERVER[$name], $this->cache[$name]);
     }
 }