Tag message must not include the signature

Signatures on tags are just tacked onto the end of the message.
Getting the message must not return the signature. Compare [1]
and [2] in C git, which both drop a signature at the end of an
object body.

[1] https://github.com/git/git/blob/21bf933/builtin/tag.c#L173
[2] https://github.com/git/git/blob/21bf933/ref-filter.c#L1276

Change-Id: Ic8a1062b8bc77f2d7c138c3fe8a7fd13b1253f38
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>

1 files changed, 36 insertions, 12 deletions

diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/RevTag.java b/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/RevTag.java
index 3bcdfafea7..3499136f92 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/RevTag.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/RevTag.java
@@ -202,24 +202,16 @@ public class RevTag extends RevObject {
 		return -1;
 	}
 
-	/**
-	 * Parse the GPG signature from the raw buffer.
-	 *
-	 * @return contents of the GPG signature; {@code null} if the tag was not
-	 *         signed.
-	 * @since 5.11
-	 */
-	@Nullable
-	public final byte[] getRawGpgSignature() {
+	private int getSignatureStart() {
 		byte[] raw = buffer;
 		int msgB = RawParseUtils.tagMessage(raw, 0);
 		if (msgB < 0) {
-			return null;
+			return msgB;
 		}
 		// Find the last signature start and return the rest
 		int start = nextStart(hSignature, raw, msgB);
 		if (start < 0) {
-			return null;
+			return start;
 		}
 		int next = RawParseUtils.nextLF(raw, start);
 		while (next < raw.length) {
@@ -230,6 +222,23 @@ public class RevTag extends RevObject {
 			start = newStart;
 			next = RawParseUtils.nextLF(raw, start);
 		}
+		return start;
+	}
+
+	/**
+	 * Parse the GPG signature from the raw buffer.
+	 *
+	 * @return contents of the GPG signature; {@code null} if the tag was not
+	 *         signed.
+	 * @since 5.11
+	 */
+	@Nullable
+	public final byte[] getRawGpgSignature() {
+		byte[] raw = buffer;
+		int start = getSignatureStart();
+		if (start < 0) {
+			return null;
+		}
 		return Arrays.copyOfRange(raw, start, raw.length);
 	}
 
@@ -249,7 +258,12 @@ public class RevTag extends RevObject {
 		if (msgB < 0) {
 			return ""; //$NON-NLS-1$
 		}
-		return RawParseUtils.decode(guessEncoding(), raw, msgB, raw.length);
+		int signatureStart = getSignatureStart();
+		int end = signatureStart < 0 ? raw.length : signatureStart;
+		if (end == msgB) {
+			return ""; //$NON-NLS-1$
+		}
+		return RawParseUtils.decode(guessEncoding(), raw, msgB, end);
 	}
 
 	/**
@@ -275,6 +289,16 @@ public class RevTag extends RevObject {
 		}
 
 		int msgE = RawParseUtils.endOfParagraph(raw, msgB);
+		int signatureStart = getSignatureStart();
+		if (signatureStart >= msgB && msgE > signatureStart) {
+			msgE = signatureStart;
+			if (msgE > msgB) {
+				msgE--;
+			}
+			if (msgB == msgE) {
+				return ""; //$NON-NLS-1$
+			}
+		}
 		String str = RawParseUtils.decode(guessEncoding(), raw, msgB, msgE);
 		if (RevCommit.hasLF(raw, msgB, msgE)) {
 			str = StringUtils.replaceLineBreaksWithSpace(str);