ensure extended attribute is completely written

Author: infeo

jfuse-tests/src/test/java/org/cryptomator/jfuse/tests/MirrorIT.java

@@ -36,7 +36,6 @@
 import java.time.Duration;
 import java.util.ArrayList;
 import java.util.List;
-import java.util.Set;
 import java.util.concurrent.TimeUnit;
 
 @EnabledIf("hasSupportedImplementation")
@@ -227,8 +226,9 @@ public void setup() throws IOException {
 		public void testSetxattr(String attrName) {
 			var attrView = Files.getFileAttributeView(file, UserDefinedFileAttributeView.class);
 			var attrValue = StandardCharsets.UTF_8.encode(attrName);
-
-			Assertions.assertDoesNotThrow(() -> attrView.write(attrName, attrValue));
+			var expectedWrittenBytes = attrValue.limit();
+			int bytesWritten = Assertions.assertDoesNotThrow(() -> attrView.write(attrName, attrValue));
+			Assertions.assertEquals(expectedWrittenBytes, bytesWritten, "The extended attribute %s was not completely written.".formatted(attrName));
 		}
 
 		@Order(2)