Fix DiffFormatter for diffs against working tree with autocrlf=true

The WorkingTreeSource produced an ObjectLoader that returned
inconsistent sizes: the file size in getSize(), but then a
correctly filtered smaller stream in openStream(). This resulted
either in an IOE "short read of block" or in an EOFException
depending on the resulting filtered size.

Fix this by ensuring that getSize() does return the size of the
filtered stream.

Bug: 530106
Change-Id: I7c7c85036047dc10030ed29c1d5a6c7f34f2bdff
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>

org.eclipse.jgit.test/tst/org/eclipse/jgit/diff/DiffFormatterTest.java

@@ -55,12 +55,14 @@
 import org.eclipse.jgit.junit.RepositoryTestCase;
 import org.eclipse.jgit.junit.TestRepository;
 import org.eclipse.jgit.lib.AnyObjectId;
+import org.eclipse.jgit.lib.ConfigConstants;
 import org.eclipse.jgit.lib.FileMode;
 import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.patch.FileHeader;
 import org.eclipse.jgit.patch.HunkHeader;
 import org.eclipse.jgit.revwalk.RevCommit;
+import org.eclipse.jgit.storage.file.FileBasedConfig;
 import org.eclipse.jgit.treewalk.FileTreeIterator;
 import org.eclipse.jgit.treewalk.filter.PathFilter;
 import org.eclipse.jgit.util.FileUtils;
@@ -485,6 +487,102 @@ public void testDiffNullToNull() throws Exception {
 		}
 	}
 
+	@Test
+	public void testDiffAutoCrlfSmallFile() throws Exception {
+		String content = "01234\r\n01234\r\n01234\r\n";
+		String expectedDiff = "diff --git a/test.txt b/test.txt\n"
+				+ "index fe25983..a44a032 100644\n" //
+				+ "--- a/test.txt\n" //
+				+ "+++ b/test.txt\n" //
+				+ "@@ -1,3 +1,4 @@\n" //
+				+ " 01234\n" //
+				+ "+ABCD\n" //
+				+ " 01234\n" //
+				+ " 01234\n";
+		doAutoCrLfTest(content, expectedDiff);
+	}
+
+	@Test
+	public void testDiffAutoCrlfMediumFile() throws Exception {
+		String content = mediumCrLfString();
+		String expectedDiff = "diff --git a/test.txt b/test.txt\n"
+				+ "index 215c502..c10f08c 100644\n" //
+				+ "--- a/test.txt\n" //
+				+ "+++ b/test.txt\n" //
+				+ "@@ -1,4 +1,5 @@\n" //
+				+ " 01234567\n" //
+				+ "+ABCD\n" //
+				+ " 01234567\n" //
+				+ " 01234567\n" //
+				+ " 01234567\n";
+		doAutoCrLfTest(content, expectedDiff);
+	}
+
+	@Test
+	public void testDiffAutoCrlfLargeFile() throws Exception {
+		String content = largeCrLfString();
+		String expectedDiff = "diff --git a/test.txt b/test.txt\n"
+				+ "index 7014942..c0487a7 100644\n" //
+				+ "--- a/test.txt\n" //
+				+ "+++ b/test.txt\n" //
+				+ "@@ -1,4 +1,5 @@\n"
+				+ " 012345678901234567890123456789012345678901234567\n"
+				+ "+ABCD\n"
+				+ " 012345678901234567890123456789012345678901234567\n"
+				+ " 012345678901234567890123456789012345678901234567\n"
+				+ " 012345678901234567890123456789012345678901234567\n";
+		doAutoCrLfTest(content, expectedDiff);
+	}
+
+	private void doAutoCrLfTest(String content, String expectedDiff)
+			throws Exception {
+		FileBasedConfig config = db.getConfig();
+		config.setString(ConfigConstants.CONFIG_CORE_SECTION, null,
+				ConfigConstants.CONFIG_KEY_AUTOCRLF, "true");
+		config.save();
+		commitFile("test.txt", content, "master");
+		// Insert a line into content
+		int i = content.indexOf('\n');
+		content = content.substring(0, i + 1) + "ABCD\r\n"
+				+ content.substring(i + 1);
+		writeTrashFile("test.txt", content);
+		// Create the patch
+		try (ByteArrayOutputStream os = new ByteArrayOutputStream();
+				DiffFormatter dfmt = new DiffFormatter(
+						new BufferedOutputStream(os))) {
+			dfmt.setRepository(db);
+			dfmt.format(new DirCacheIterator(db.readDirCache()),
+					new FileTreeIterator(db));
+			dfmt.flush();
+
+			String actual = os.toString("UTF-8");
+
+			assertEquals(expectedDiff, actual);
+		}
+	}
+
+	private static String largeCrLfString() {
+		String line = "012345678901234567890123456789012345678901234567\r\n";
+		StringBuilder builder = new StringBuilder(
+				2 * RawText.FIRST_FEW_BYTES);
+		while (builder.length() < 2 * RawText.FIRST_FEW_BYTES) {
+			builder.append(line);
+		}
+		return builder.toString();
+	}
+
+	private static String mediumCrLfString() {
+		// Create a CR-LF string longer than RawText.FIRST_FEW_BYTES whose
+		// canonical representation is shorter than RawText.FIRST_FEW_BYTES.
+		String line = "01234567\r\n"; // 10 characters
+		StringBuilder builder = new StringBuilder(
+				RawText.FIRST_FEW_BYTES + line.length());
+		while (builder.length() <= RawText.FIRST_FEW_BYTES) {
+			builder.append(line);
+		}
+		return builder.toString();
+	}
+
 	private static String makeDiffHeader(String pathA, String pathB,
 			ObjectId aId,
 			ObjectId bId) {

org.eclipse.jgit/src/org/eclipse/jgit/diff/ContentSource.java

@@ -170,10 +170,11 @@ public long size(String path, ObjectId id) throws IOException {
 		@Override
 		public ObjectLoader open(String path, ObjectId id) throws IOException {
 			seek(path);
+			long entrySize = ptr.getEntryContentLength();
 			return new ObjectLoader() {
 				@Override
 				public long getSize() {
-					return ptr.getEntryLength();
+					return entrySize;
 				}
 
 				@Override
@@ -184,7 +185,7 @@ public int getType() {
 				@Override
 				public ObjectStream openStream() throws MissingObjectException,
 						IOException {
-					long contentLength = ptr.getEntryContentLength();
+					long contentLength = entrySize;
 					InputStream in = ptr.openEntryStream();
 					in = new BufferedInputStream(in);
 					return new ObjectStream.Filter(getType(), contentLength, in);

org.eclipse.jgit/src/org/eclipse/jgit/diff/RawText.java

@@ -74,7 +74,7 @@ public class RawText extends Sequence {
 	public static final RawText EMPTY_TEXT = new RawText(new byte[0]);
 
 	/** Number of bytes to check for heuristics in {@link #isBinary(byte[])} */
-	private static final int FIRST_FEW_BYTES = 8000;
+	static final int FIRST_FEW_BYTES = 8000;
 
 	/** The file content for this sequence. */
 	protected final byte[] content;