add better check for blank user key

Author: Dan Richelson

src/LaunchDarkly/LDClient.php

@@ -111,7 +111,7 @@ public function variation($key, $user, $default = false) {
         }
 
         try {
-            if (is_null($user) || $user->getKey() === null ) {
+            if (is_null($user) || is_null($user->getKey())) {
                 $this->_sendFlagRequestEvent($key, $user, $default, $default);
                 $this->_logger->warn("Variation called with null user or null user key! Returning default value");
                 return $default;

tests/LDUserTest.php

@@ -105,6 +105,7 @@ public function testLDUserBlankKey() {
         $builder = new LDUserBuilder("");
         $user = $builder->build();
         $this->assertTrue($user->isKeyBlank());
+        $this->assertFalse(is_null($user->getKey()));
 
         $builder = new LDUserBuilder("key");
         $user = $builder->build();
@@ -113,7 +114,6 @@ public function testLDUserBlankKey() {
         $builder = new LDUserBuilder(null);
         $user = $builder->build();
         $this->assertFalse($user->isKeyBlank());
-
     }
 }