FooterLine: First line cannot be a footer

The first line of the commit message cannot be a footer line. This
restriction was dropped in commit [1] while adding multiline
footers. This affects at least the git-numberer gerrit plugin, that
even have a test for it [2].

Reintroduce the restriction that the first line of the commit message
cannot be a footer and bring the test from git-numberer to jgit.

[1] https://review.gerrithub.io/c/eclipse-jgit/jgit/+/1172664
[2] https://chromium.googlesource.com/infra/gerrit-plugins/git-numberer/+/refs/heads/main/src/test/java/com/googlesource/chromium/plugins/gitnumberer/GetFooterLinesTest.java

Change-Id: Id3fa6b8614664dbc3fdccffe1006b0b9752a8de6

1 files changed, 20 insertions, 0 deletions

diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/revwalk/FooterLineTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/revwalk/FooterLineTest.java
index 303aedcd00..ca6fd4644e 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/revwalk/FooterLineTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/revwalk/FooterLineTest.java
@@ -369,6 +369,26 @@ public class FooterLineTest extends RepositoryTestCase {
 				f.getValue());
 	}
 
+	@Test
+	public void testFirstLineNeverFooter() {
+		String msg = buildMessage(
+				String.join("\n", "First-Line: is never a footer", "Foo: ter",
+						"1-is: also a footer"));
+		List<FooterLine> footers = FooterLine.fromMessage(msg);
+		assertNotNull(footers);
+		assertEquals(2, footers.size());
+	}
+
+	@Test
+	public void testLineAfterFooters() {
+		String msg = buildMessage(
+				String.join("\n", "Subject line: is never a footer", "Foo: ter",
+						"1-is: also a footer", "this is not a footer"));
+		List<FooterLine> footers = FooterLine.fromMessage(msg);
+		assertNotNull(footers);
+		assertEquals(2, footers.size());
+	}
+
 	private String buildMessage(String msg) {
 		StringBuilder buf = new StringBuilder();
 		buf.append("tree " + ObjectId.zeroId().name() + "\n");