1 files changed, 51 insertions, 14 deletions

diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/RevCommit.java b/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/RevCommit.java
index c23e4e3288..e67ada6022 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/RevCommit.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/RevCommit.java
@@ -44,12 +44,17 @@
 
 package org.eclipse.jgit.revwalk;
 
+import static java.nio.charset.StandardCharsets.UTF_8;
+
 import java.io.IOException;
 import java.nio.charset.Charset;
+import java.nio.charset.IllegalCharsetNameException;
+import java.nio.charset.UnsupportedCharsetException;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
 
+import org.eclipse.jgit.annotations.Nullable;
 import org.eclipse.jgit.errors.IncorrectObjectTypeException;
 import org.eclipse.jgit.errors.MissingObjectException;
 import org.eclipse.jgit.lib.AnyObjectId;
@@ -441,12 +446,12 @@ public class RevCommit extends RevObject {
 	 * @return decoded commit message as a string. Never null.
 	 */
 	public final String getFullMessage() {
-		final byte[] raw = buffer;
-		final int msgB = RawParseUtils.commitMessage(raw, 0);
-		if (msgB < 0)
+		byte[] raw = buffer;
+		int msgB = RawParseUtils.commitMessage(raw, 0);
+		if (msgB < 0) {
 			return ""; //$NON-NLS-1$
-		final Charset enc = RawParseUtils.parseEncoding(raw);
-		return RawParseUtils.decode(enc, raw, msgB, raw.length);
+		}
+		return RawParseUtils.decode(guessEncoding(), raw, msgB, raw.length);
 	}
 
 	/**
@@ -465,16 +470,17 @@ public class RevCommit extends RevObject {
 	 *         spanned multiple lines. Embedded LFs are converted to spaces.
 	 */
 	public final String getShortMessage() {
-		final byte[] raw = buffer;
-		final int msgB = RawParseUtils.commitMessage(raw, 0);
-		if (msgB < 0)
+		byte[] raw = buffer;
+		int msgB = RawParseUtils.commitMessage(raw, 0);
+		if (msgB < 0) {
 			return ""; //$NON-NLS-1$
+		}
 
-		final Charset enc = RawParseUtils.parseEncoding(raw);
-		final int msgE = RawParseUtils.endOfParagraph(raw, msgB);
-		String str = RawParseUtils.decode(enc, raw, msgB, msgE);
-		if (hasLF(raw, msgB, msgE))
+		int msgE = RawParseUtils.endOfParagraph(raw, msgB);
+		String str = RawParseUtils.decode(guessEncoding(), raw, msgB, msgE);
+		if (hasLF(raw, msgB, msgE)) {
 			str = StringUtils.replaceLineBreaksWithSpace(str);
+		}
 		return str;
 	}
 
@@ -488,18 +494,49 @@ public class RevCommit extends RevObject {
 	/**
 	 * Determine the encoding of the commit message buffer.
 	 * <p>
+	 * Locates the "encoding" header (if present) and returns its value. Due to
+	 * corruption in the wild this may be an invalid encoding name that is not
+	 * recognized by any character encoding library.
+	 * <p>
+	 * If no encoding header is present, null.
+	 *
+	 * @return the preferred encoding of {@link #getRawBuffer()}; or null.
+	 * @since 4.2
+	 */
+	@Nullable
+	public final String getEncodingName() {
+		return RawParseUtils.parseEncodingName(buffer);
+	}
+
+	/**
+	 * Determine the encoding of the commit message buffer.
+	 * <p>
 	 * Locates the "encoding" header (if present) and then returns the proper
 	 * character set to apply to this buffer to evaluate its contents as
 	 * character data.
 	 * <p>
-	 * If no encoding header is present, {@link Constants#CHARSET} is assumed.
+	 * If no encoding header is present {@code UTF-8} is assumed.
 	 *
 	 * @return the preferred encoding of {@link #getRawBuffer()}.
+	 * @throws IllegalCharsetNameException
+	 *             if the character set requested by the encoding header is
+	 *             malformed and unsupportable.
+	 * @throws UnsupportedCharsetException
+	 *             if the JRE does not support the character set requested by
+	 *             the encoding header.
 	 */
 	public final Charset getEncoding() {
 		return RawParseUtils.parseEncoding(buffer);
 	}
 
+	private Charset guessEncoding() {
+		try {
+			return getEncoding();
+		} catch (IllegalCharsetNameException | UnsupportedCharsetException e) {
+			return UTF_8;
+		}
+	}
+
 	/**
 	 * Parse the footer lines (e.g. "Signed-off-by") for machine processing.
 	 * <p>
@@ -529,7 +566,7 @@ public class RevCommit extends RevObject {
 
 		final int msgB = RawParseUtils.commitMessage(raw, 0);
 		final ArrayList<FooterLine> r = new ArrayList<FooterLine>(4);
-		final Charset enc = getEncoding();
+		final Charset enc = guessEncoding();
 		for (;;) {
 			ptr = RawParseUtils.prevLF(raw, ptr);
 			if (ptr <= msgB)