[findbugs] Do not ignore exceptional return value of createNewFile()

Properly handle return value of java.io.File.createNewFile().

Change-Id: I3a74cc84cd126ca1a0eaccc77b2944d783ff0747
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

org.eclipse.jgit.http.test/tst/org/eclipse/jgit/http/test/FileResolverTest.java

@@ -47,7 +47,6 @@ import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNull;
-import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
 import java.io.File;
@@ -58,6 +57,7 @@ import org.eclipse.jgit.http.server.resolver.FileResolver;
 import org.eclipse.jgit.http.server.resolver.ServiceNotEnabledException;
 import org.eclipse.jgit.junit.LocalDiskRepositoryTestCase;
 import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.util.FileUtils;
 import org.junit.Test;
 
 public class FileResolverTest extends LocalDiskRepositoryTestCase {
@@ -116,8 +116,7 @@ public class FileResolverTest extends LocalDiskRepositoryTestCase {
 			fail("did not honor export-all flag");
 		}
 
-		export.createNewFile();
-		assertTrue("has git-daemon-export-ok", export.exists());
+		FileUtils.createNewFile(export);
 		resolver = new FileResolver(base, false /* require flag */);
 		try {
 			resolver.open(null, name).close();

org.eclipse.jgit.test/tst/org/eclipse/jgit/treewalk/filter/IndexDiffFilterTest.java

@@ -56,6 +56,7 @@ import org.eclipse.jgit.lib.RepositoryTestCase;
 import org.eclipse.jgit.revwalk.RevCommit;
 import org.eclipse.jgit.treewalk.FileTreeIterator;
 import org.eclipse.jgit.treewalk.TreeWalk;
+import org.eclipse.jgit.util.FileUtils;
 import org.junit.Before;
 import org.junit.Test;
 
@@ -537,8 +538,7 @@ public class IndexDiffFilterTest extends RepositoryTestCase {
 
 	private void createEmptyFolder() throws Exception {
 		File path = new File(db.getWorkTree(), FOLDER);
-		path.mkdir();
-		assertTrue(path.isDirectory());
+		FileUtils.mkdir(path);
 	}
 
 	private RevCommit createEmptyFolderAndCommit() throws Exception {
@@ -548,14 +548,12 @@ public class IndexDiffFilterTest extends RepositoryTestCase {
 
 	private void createEmptyFolderUntracked() throws Exception {
 		File path = new File(db.getWorkTree(), UNTRACKED_FOLDER);
-		path.mkdir();
-		assertTrue(path.isDirectory());
+		FileUtils.mkdir(path);
 	}
 
 	private void createEmptyFolderIgnored() throws Exception {
 		File path = new File(db.getWorkTree(), IGNORED_FOLDER);
-		path.mkdir();
-		assertTrue(path.isDirectory());
+		FileUtils.mkdir(path);
 		writeTrashFile(GITIGNORE, GITIGNORE + "\n" + IGNORED_FOLDER + "/");
 	}