Fix computation of id in WorkingTreeIterator with autocrlf and smudging

JGit failed to do checkouts when the index contained smudged entries and
autocrlf was on. In such cases the WorkingTreeIterator calculated the
SHA1 sometimes on content which was not correctly filtered. The SHA1 was
computed on content which two times went through a lf->crlf conversion.

We used to tell the treewalk whether it is a checkin or checkout
operation and always use the related filters when reading any content.
If on windows and autocrlf is true and we do a checkout operation then
we always used a lf->crlf conversion on any text content. That's not
correct. Even during a checkout we sometimes need the crlf->lf
conversion. E.g. when calculating the content-id for working-tree
content we need to use crlf->lf filtering although the overall operation
type is checkout.

Often this bug does not have effects because we seldom compute the
content-id of filesystem content during a checkout. But we do need to
know whether a file is dirty or not before we overwrite it during a
checkout. And if the index entries are smudged we don't trust the index
and compute filesystem-content-sha1's explicitly.

This caused EGit not to be able to switch branches anymore on Windows
when autocrlf was true. EGit denied the checkout because it thought
workingtree files are dirty because content-sha1 are computed on wrongly
filtered content.

Bug: 493360
Change-Id: I1072a57b4c529ba3aaa50b7b02d2b816bb64a9b8
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
3 files changed
tree: 04afc8c0231486d5d0ab4d0ab92ed44a20b165d1
  1. lib/
  2. org.eclipse.jgit/
  3. org.eclipse.jgit.ant/
  4. org.eclipse.jgit.ant.test/
  5. org.eclipse.jgit.archive/
  6. org.eclipse.jgit.http.apache/
  7. org.eclipse.jgit.http.server/
  8. org.eclipse.jgit.http.test/
  9. org.eclipse.jgit.junit/
  10. org.eclipse.jgit.junit.http/
  11. org.eclipse.jgit.lfs/
  12. org.eclipse.jgit.lfs.server/
  13. org.eclipse.jgit.lfs.server.test/
  14. org.eclipse.jgit.lfs.test/
  15. org.eclipse.jgit.packaging/
  16. org.eclipse.jgit.pgm/
  17. org.eclipse.jgit.pgm.test/
  18. org.eclipse.jgit.test/
  19. org.eclipse.jgit.ui/
  20. tools/
  21. .buckconfig
  22. .buckversion
  23. .gitattributes
  24. .gitignore
  25. .mailmap
  26. BUCK
  27. CONTRIBUTING.md
  28. LICENSE
  29. pom.xml
  30. README.md
README.md

Java Git

An implementation of the Git version control system in pure Java.

This package is licensed under the EDL (Eclipse Distribution License).

JGit can be imported straight into Eclipse, built and tested from there, but the automated builds use Maven.

  • org.eclipse.jgit

    A pure Java library capable of being run standalone, with no additional support libraries. It provides classes to read and write a Git repository and operate on a working directory.

    All portions of JGit are covered by the EDL. Absolutely no GPL, LGPL or EPL contributions are accepted within this package.

  • org.eclipse.jgit.java7

    Extensions for users of Java 7.

  • org.eclipse.jgit.ant

    Ant tasks based on JGit.

  • org.eclipse.jgit.archive

    Support for exporting to various archive formats (zip etc).

  • org.eclipse.jgit.http.apache

    Apache httpclient support

  • org.eclipse.jgit.http.server

    Server for the smart and dumb Git HTTP protocol.

  • org.eclipse.jgit.pgm

    Command-line interface Git commands implemented using JGit (“pgm” stands for program).

  • org.eclipse.jgit.packaging

    Production of Eclipse features and p2 repository for JGit. See the JGit Wiki on why and how to use this module.

Tests

  • org.eclipse.jgit.junit

    Helpers for unit testing

  • org.eclipse.jgit.test

    Unit tests for org.eclipse.jgit

  • org.eclipse.jgit.java7.test

    Unit tests for Java 7 specific features

  • org.eclipse.jgit.ant.test

  • org.eclipse.jgit.pgm.test

  • org.eclipse.jgit.http.test

  • org.eclipse.jgit.junit.test

    No further description needed

Warnings/Caveats

  • Native smbolic links are supported, but only if you are using Java 7 or newer and include the org.eclipse.jgit.java7 jar/bundle in the classpath, provided the file system supports them. For Windows you must have Windows Vista/Windows 2008 or newer, use a non-administrator account and have the SeCreateSymbolicLinkPrivilege.

  • Only the timestamp of the index is used by jgit if the index is dirty.

  • JGit requires at least a Java 7 JDK.

  • CRLF conversion is performed depending on the core.autocrlf setting, however Git for Windows by default stores that setting during installation in the “system wide” configuration file. If Git is not installed, use the global or repository configuration for the core.autocrlf setting.

  • The system wide configuration file is located relative to where C Git is installed. Make sure Git can be found via the PATH environment variable. When installing Git for Windows check the “Run Git from the Windows Command Prompt” option. There are other options like Eclipse settings that can be used for pointing out where C Git is installed. Modifying PATH is the recommended option if C Git is installed.

  • We try to use the same notation of $HOME as C Git does. On Windows this is often not the same value as the user.home system property.

Package Features

  • org.eclipse.jgit/

    • Read loose and packed commits, trees, blobs, including deltafied objects.

    • Read objects from shared repositories

    • Write loose commits, trees, blobs.

    • Write blobs from local files or Java InputStreams.

    • Read blobs as Java InputStreams.

    • Copy trees to local directory, or local directory to a tree.

    • Lazily loads objects as necessary.

    • Read and write .git/config files.

    • Create a new repository.

    • Read and write refs, including walking through symrefs.

    • Read, update and write the Git index.

    • Checkout in dirty working directory if trivial.

    • Walk the history from a given set of commits looking for commits introducing changes in files under a specified path.

    • Object transport Fetch via ssh, git, http, Amazon S3 and bundles. Push via ssh, git and Amazon S3. JGit does not yet deltify the pushed packs so they may be a lot larger than C Git packs.

    • Garbage collection

    • Merge

    • Rebase

    • And much more

  • org.eclipse.jgit.pgm/

    • Assorted set of command line utilities. Mostly for ad-hoc testing of jgit log, glog, fetch etc.
  • org.eclipse.jgit.java7/

    • Support for symbolic links.

    • Optimizations for reading file system attributes

  • org.eclipse.jgit.ant/

    • Ant tasks
  • org.eclipse.jgit.archive/

    • Support for Zip/Tar and other formats
  • org.eclipse.http.*/

    • HTTP client and server support

Missing Features

There are some missing features:

  • gitattributes support

Support

Post question, comments or patches to the jgit-dev@eclipse.org mailing list. You need to be subscribed to post, see here:

https://dev.eclipse.org/mailman/listinfo/jgit-dev

Contributing

See the EGit Contributor Guide:

http://wiki.eclipse.org/EGit/Contributor_Guide

About Git

More information about Git, its repository format, and the canonical C based implementation can be obtained from the Git website:

http://git-scm.com/