Description Thomas Stock 2020-07-09 05:45:11 EDT

jgit marks a commited file that was later added to gitignore as deleted.

here is a unit test that shows the problem

My local git version is 2.27.0

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package any;

import static org.junit.Assert.assertEquals;

import java.io.BufferedOutputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.OutputStream;
import java.util.List;

import org.eclipse.jgit.api.Git;
import org.eclipse.jgit.api.errors.GitAPIException;
import org.eclipse.jgit.api.errors.JGitInternalException;
import org.eclipse.jgit.diff.DiffEntry;
import org.eclipse.jgit.diff.DiffFormatter;
import org.eclipse.jgit.diff.RawTextComparator;
import org.eclipse.jgit.dircache.DirCacheIterator;
import org.eclipse.jgit.junit.RepositoryTestCase;
import org.eclipse.jgit.lib.Repository;
import org.eclipse.jgit.treewalk.AbstractTreeIterator;
import org.eclipse.jgit.treewalk.FileTreeIterator;
import org.junit.Test;

public class TestDiffFor extends RepositoryTestCase {

  @Test
  public void testEmptyLevel() throws IOException, GitAPIException {
    File emptyFolder = new File(db.getWorkTree(), "empty");
    emptyFolder.mkdir();
    File emptyChildFolder = new File(emptyFolder, "empty");
    emptyChildFolder.mkdir();
    // mkdir -p empty/empty
    File keep = new File(emptyChildFolder, ".gitkeep");
    write(keep, "");
    // touch empty/empty/.gitkeep

    try (Git git = new Git(db)) {
      git.add().addFilepattern(".").call();
      // git add -A
      git.commit().setMessage("Initial commit").call();
      // git commit -am "Initial commit"
      // https://git-scm.com/docs/gitignore
      write(new File(db.getWorkTree(), ".gitignore"), "empty/*"); // maybe in jgit ".*" is valid in git "*"?
      // echo "empty/*" > .gitignore
      git.add().addFilepattern(".").call();
      // git add -A
      git.commit().setMessage("Added ignore").call();
      // git commit -am "Added ignore"
      assertEquals("", formatDiff(git));
      // works with 4.11.9.201909030838-r
      // fails with 5.0.0.201806131550-r, 5.1.13.202002110435-r, 5.8.0.202006091008-r
      // git diff # is empty
    }
  }

  private static String formatDiff(Git git) {
    OutputStream out = new ByteArrayOutputStream();
    Repository repo = git.getRepository();
    DiffFormatter diffFmt = new DiffFormatter(new BufferedOutputStream(out));
    diffFmt.setRepository(repo);
    diffFmt.setDiffComparator(RawTextComparator.WS_IGNORE_TRAILING);
    try {
      AbstractTreeIterator oldTree = new DirCacheIterator(repo.readDirCache());
      AbstractTreeIterator newTree = new FileTreeIterator(repo);

      List<DiffEntry> result = diffFmt.scan(oldTree, newTree);
      diffFmt.format(result);

      diffFmt.flush();
    } catch (IOException e) {
      throw new JGitInternalException(e.getMessage(), e);
    } finally {
      diffFmt.close();
    }

    return out.toString();
  }
}