Allow repeated calls to DrupalKernel::setSitePath()

Needs test.

Added a test.

+++ b/core/tests/Drupal/KernelTests/Core/DrupalKernel/DrupalKernelTest.php
@@ -184,6 +184,16 @@ public function testPreventChangeOfSitePath() {
+    $logic_exception = FALSE;
+    $path = $kernel->getSitePath();
+    try {
+      $kernel->setSitePath($path);
+    }
+    catch (\LogicException $e) {
+      $logic_exception = TRUE;
+    }
+    $this->assertFalse($logic_exception, 'Does not throw LogicException if DrupalKernel::setSitePath() is called with identical path after boot');

I know you copied the exception logic from further above, but this is really verbose and not necessary. We can just call setSitePath() again and add a nice comment above from the assertFalse(). If the exception is thrown then the test fails because phpunit catches it.

Makes sense.

Oops. Now the patch and the test.

Cool, thanks!

Committed 16842fc and pushed to 8.4.x. Thanks!