Skip some tests when the runtime cannot handle Unicode file paths

When executing a test with LANG environment variable set to non UTF-8
encoding, it seems that JRE cannot handle Unicode file paths. This
happens when this test is executed in Bazel as it unsets LANG
(https://docs.bazel.build/versions/master/test-encyclopedia.html#initial-conditions).

Skip the test if the runtime cannot handle Unicode file paths.

Change-Id: I16bd3cd959dbaf2335b9c5202873e2f12ed0ba21
Signed-off-by: Masaya Suzuki <masayasuzuki@google.com>

org.eclipse.jgit.test/tst/org/eclipse/jgit/treewalk/FileTreeIteratorTest.java

@@ -48,9 +48,11 @@ import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertTrue;
+import static org.junit.Assume.assumeNoException;
 
 import java.io.File;
 import java.io.IOException;
+import java.nio.file.InvalidPathException;
 import java.security.MessageDigest;
 
 import org.eclipse.jgit.api.Git;
@@ -666,9 +668,23 @@ public class FileTreeIteratorTest extends RepositoryTestCase {
 	public void testFileModeSymLinkIsNotATree() throws IOException {
 		org.junit.Assume.assumeTrue(FS.DETECTED.supportsSymlinks());
 		FS fs = db.getFS();
-		// mål = target in swedish, just to get som unicode in here
+		// mål = target in swedish, just to get some unicode in here
 		writeTrashFile("mål/data", "targetdata");
-		fs.createSymLink(new File(trash, "länk"), "mål");
+		File file = new File(trash, "länk");
+
+		try {
+			file.toPath();
+		} catch (InvalidPathException e) {
+			// When executing a test with LANG environment variable set to non
+			// UTF-8 encoding, it seems that JRE cannot handle Unicode file
+			// paths. This happens when this test is executed in Bazel as it
+			// unsets LANG
+			// (https://docs.bazel.build/versions/master/test-encyclopedia.html#initial-conditions).
+			// Skip the test if the runtime cannot handle Unicode characters.
+			assumeNoException(e);
+		}
+
+		fs.createSymLink(file, "mål");
 		FileTreeIterator fti = new FileTreeIterator(db);
 		assertFalse(fti.eof());
 		while (!fti.getEntryPathString().equals("länk")) {

org.eclipse.jgit.test/tst/org/eclipse/jgit/util/FSTest.java

@@ -47,11 +47,13 @@ import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assume.assumeTrue;
+import static org.junit.Assume.assumeNoException;
 
 import java.io.File;
 import java.io.IOException;
 import java.nio.charset.Charset;
 import java.nio.file.Files;
+import java.nio.file.InvalidPathException;
 import java.nio.file.attribute.PosixFileAttributeView;
 import java.nio.file.attribute.PosixFilePermission;
 import java.util.Set;
@@ -92,16 +94,17 @@ public class FSTest {
 	public void testSymlinkAttributes() throws IOException, InterruptedException {
 		Assume.assumeTrue(FS.DETECTED.supportsSymlinks());
 		FS fs = FS.DETECTED;
-		File link = new File(trash, "ä");
-		File target = new File(trash, "å");
-		fs.createSymLink(link, "å");
+		File link = new File(trash, "a");
+		File target = new File(trash, "b");
+		fs.createSymLink(link, "b");
 		assertTrue(fs.exists(link));
 		String targetName = fs.readSymLink(link);
-		assertEquals("å", targetName);
+		assertEquals("b", targetName);
 		assertTrue(fs.lastModified(link) > 0);
 		assertTrue(fs.exists(link));
 		assertFalse(fs.canExecute(link));
-		assertEquals(2, fs.length(link));
+		// The length of a symbolic link is a length of the target file path.
+		assertEquals(1, fs.length(link));
 		assertFalse(fs.exists(target));
 		assertFalse(fs.isFile(target));
 		assertFalse(fs.isDirectory(target));
@@ -120,6 +123,32 @@ public class FSTest {
 		assertTrue(fs.canExecute(target));
 	}
 
+	@Test
+	public void testUnicodeFilePath() throws IOException {
+		Assume.assumeTrue(FS.DETECTED.supportsSymlinks());
+		FS fs = FS.DETECTED;
+		File link = new File(trash, "ä");
+		File target = new File(trash, "å");
+
+		try {
+			// Check if the runtime can support Unicode file paths.
+			link.toPath();
+			target.toPath();
+		} catch (InvalidPathException e) {
+			// When executing a test with LANG environment variable set to non
+			// UTF-8 encoding, it seems that JRE cannot handle Unicode file
+			// paths. This happens when this test is executed in Bazel as it
+			// unsets LANG
+			// (https://docs.bazel.build/versions/master/test-encyclopedia.html#initial-conditions).
+			// Skip the test if the runtime cannot handle Unicode characters.
+			assumeNoException(e);
+		}
+
+		fs.createSymLink(link, "å");
+		assertTrue(fs.exists(link));
+		assertEquals("å", fs.readSymLink(link));
+	}
+
 	@Test
 	public void testExecutableAttributes() throws Exception {
 		FS fs = FS.DETECTED.newInstance();