Fix: do not unset authScheme property

Also unset loop variables bound by reference to array elements after the
loop to avoid possible surprises in the future.

CHANGELOG.md

@@ -1,9 +1,12 @@
 # Changelog for CardDAV client library for PHP ("PHP-CardDavClient")
 
-## Version 1.X.Y (to 1.2.2)
+## Version 1.2.3 (to 1.2.2)
 
 - Fix: Throw an exception in the Discovery service in case no addressbook home could be discovered. Previously, an empty
        list would be returned without indication that the discovery was not successful.
+- Fix: After failure to authenticate with the server, the CardDavClient object might be left in a state that causes a
+       PHP warning on next usage (a property of the object was unintentionally deleted in that case and the warning
+       would be triggered on next attempt to access that property).
 
 ## Version 1.2.2 (to 1.2.1)
 

src/HttpClientAdapterGuzzle.php

@@ -183,7 +183,7 @@ public function sendRequest(string $method, string $uri, array $options = []): P
 
                 if ($response->getStatusCode() >= 400) {
                     Config::$logger->debug("None of the available auth schemes worked");
-                    unset($this->authScheme);
+                    $this->authScheme = null;
                 }
             }
 

src/Services/Sync.php

@@ -152,6 +152,7 @@ private function synchronizeOneBatch(
                     ] = $abook->getCard($objref["uri"]);
                 }
             }
+            unset($objref);
 
             if ($syncResult->createVCards() === false) {
                 Config::$logger->warning("Not for all changed objects, the VCard data was provided by the server");
@@ -365,6 +366,7 @@ function (array $changeObj): string {
                 Config::$logger->warning("Server did not return data for $couri");
             }
         }
+        unset($objref);
     }
 }
 

src/Services/SyncResult.php

@@ -90,6 +90,7 @@ public function createVCards(): bool
                 }
             }
         }
+        unset($obj);
 
         return $ret;
     }

tests/TestLogger.php

@@ -127,6 +127,7 @@ public function expectMessage(string $expLevel, string $expMsg): void
                 break;
             }
         }
+        unset($recMsg);
 
         TestCase::assertTrue($found, "The expected log entry containing '$expMsg' with level $expLevel was not found");
     }