diff --git a/changelog/unreleased/39016 b/changelog/unreleased/39016
new file mode 100644
index 000000000000..f0a4b78fbc55
--- /dev/null
+++ b/changelog/unreleased/39016
@@ -0,0 +1,3 @@
+Bugfix: Update file size in cache after writing empty content to non-empty file
+
+https://github.com/owncloud/core/pull/39016
diff --git a/lib/private/Files/Cache/Cache.php b/lib/private/Files/Cache/Cache.php
index 5dc8a1a9bd01..fde771184e64 100644
--- a/lib/private/Files/Cache/Cache.php
+++ b/lib/private/Files/Cache/Cache.php
@@ -359,6 +359,9 @@ public function update($id, array $data) {
 				if ($value === '') {
 					$data[$param] = null;
 				}
+				if ($value === null && \in_array($param, ['mtime', 'storage_mtime'], true)) {
+					$data[$param] = 0;
+				}
 			}
 		}
 
@@ -429,7 +432,7 @@ protected function buildParts(array $data) {
 		$params = [];
 		$queryParts = [];
 		foreach ($data as $name => $value) {
-			if (\array_search($name, $fields) !== false) {
+			if (\in_array($name, $fields, true)) {
 				if ($name === 'path') {
 					$params[] = \md5($value);
 					$queryParts[] = '`path_hash`';
diff --git a/lib/private/Files/View.php b/lib/private/Files/View.php
index 9bd55a420c3b..09fe7049aa0e 100644
--- a/lib/private/Files/View.php
+++ b/lib/private/Files/View.php
@@ -1233,7 +1233,7 @@ private function basicOperation($operation, $path, $hooks = [], $extraParam = nu
 					throw $e;
 				}
 
-				if ($result) {
+				if ($result !== false) {
 					if (\in_array('delete', $hooks)) {
 						$this->removeUpdate($storage, $internalPath);
 					}
diff --git a/tests/lib/Files/ViewTest.php b/tests/lib/Files/ViewTest.php
index 61b15a2dd5f6..edce5a0412ea 100644
--- a/tests/lib/Files/ViewTest.php
+++ b/tests/lib/Files/ViewTest.php
@@ -119,7 +119,7 @@ protected function tearDown(): void {
 		\OC_User::setUserId($this->user);
 		foreach ($this->storages as $storage) {
 			$cache = $storage->getCache();
-			$ids = $cache->getAll();
+			$cache->getAll();
 			$cache->clear();
 		}
 
@@ -1886,7 +1886,7 @@ function () use ($view, $lockedPath, &$lockTypeDuring, $operation) {
 					$lockTypeDuring = $this->getFileLockType($view, $lockedPath);
 
 					if ($operation === 'fopen') {
-						return \fopen('data://text/plain,test', 'r');
+						return \fopen('data://text/plain,test', 'rb');
 					}
 					return true;
 				}
@@ -2752,4 +2752,27 @@ public function testDeleteNonShareFolder($shareFolder, $deleteFolder) {
 		$view->mkdir($deleteFolder);
 		$this->assertTrue($view->rmdir($deleteFolder));
 	}
+
+	public function testCacheSizeUpdatedWhenEmptyingFile(): void {
+		$storage1 = $this->getTestStorage();
+		Filesystem::mount($storage1, [], '/');
+
+		$rootView = new View('');
+
+		# test with string as $data
+		$rootView->file_put_contents('welcome.txt', '1234567890');
+		$this->assertEquals(10, $rootView->filesize('welcome.txt'));
+
+		$rootView->file_put_contents('welcome.txt', '');
+		$this->assertEquals(0, $rootView->filesize('welcome.txt'));
+
+		# test with resource as $data
+		$stream = fopen('data://text/plain,1234567890', 'rb');
+		$rootView->file_put_contents('welcome.txt', $stream);
+		$this->assertEquals(10, $rootView->filesize('welcome.txt'));
+
+		$stream = fopen('data://text/plain,', 'rb');
+		$rootView->file_put_contents('welcome.txt', '');
+		$this->assertEquals(0, $rootView->filesize('welcome.txt'));
+	}
 }