From e163543cbbd10ed4595ba6568dc849a42d9e4c74 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=B6rn=20Friedrich=20Dreyer?= <jfd@butonic.de>
Date: Wed, 4 Jul 2018 16:50:47 +0200
Subject: [PATCH] empty path has no parents
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Signed-off-by: Jörn Friedrich Dreyer <jfd@butonic.de>
---
 lib/private/Files/Cache/Propagator.php   |  7 +++++++
 tests/lib/Files/Cache/PropagatorTest.php | 19 +++++++++++++++++++
 2 files changed, 26 insertions(+)

diff --git a/lib/private/Files/Cache/Propagator.php b/lib/private/Files/Cache/Propagator.php
index 5b9d19163dd2..a7ec27896cef 100644
--- a/lib/private/Files/Cache/Propagator.php
+++ b/lib/private/Files/Cache/Propagator.php
@@ -62,6 +62,10 @@ public function propagateChange($internalPath, $time, $sizeDifference = 0) {
 
 		$parents = $this->getParents($internalPath);
 
+		if (\count($parents) === 0) {
+			return;
+		}
+
 		if ($this->inBatch) {
 			foreach ($parents as $parent) {
 				$this->addToBatch($parent, $time, $sizeDifference);
@@ -99,6 +103,9 @@ public function propagateChange($internalPath, $time, $sizeDifference = 0) {
 	}
 
 	protected function getParents($path) {
+		if ($path === '') {
+			return [];
+		}
 		$parts = \explode('/', $path);
 		$parent = '';
 		$parents = [];
diff --git a/tests/lib/Files/Cache/PropagatorTest.php b/tests/lib/Files/Cache/PropagatorTest.php
index 3a73dea9e374..95870ab8cdec 100644
--- a/tests/lib/Files/Cache/PropagatorTest.php
+++ b/tests/lib/Files/Cache/PropagatorTest.php
@@ -81,6 +81,25 @@ public function testSizePropagation() {
 		}
 	}
 
+	public function getParentsProvider() {
+		return [
+			['', []],
+			['foo', ['']],
+			['foo/bar', ['', 'foo']],
+			['foo/bar/baz.txt', ['', 'foo', 'foo/bar']]
+		];
+	}
+
+	/**
+	 * @dataProvider getParentsProvider
+	 * @param $path
+	 * @throws \OCP\Files\StorageNotAvailableException
+	 */
+	public function testGetParents($path, $expected) {
+		$propagator = $this->storage->getPropagator();
+		self::assertSame($expected, self::invokePrivate($propagator, 'getParents', [$path]));
+	}
+
 	public function testBatchedPropagation() {
 		$this->storage->mkdir('foo/baz');
 		$this->storage->mkdir('asd');