On Tue, Sep 25, 2018 at 8:01 PM Stefan Beller <sbeller@xxxxxxxxxx> wrote: > > On Tue, Sep 25, 2018 at 7:30 AM Derrick Stolee <stolee@xxxxxxxxx> wrote: > > > > On 9/25/2018 3:06 AM, Patrick Steinhardt wrote: > > > On Mon, Sep 24, 2018 at 11:32:23PM +0200, SZEDER Gábor wrote: > > >> On Mon, Sep 24, 2018 at 02:15:30PM -0700, Derrick Stolee via GitGitGadget wrote: > > >>> From: Derrick Stolee <dstolee@xxxxxxxxxxxxx> > > >>> > > >>> The index v4 format has been available since 2012 with 9d22778 > > >>> "reach-cache.c: write prefix-compressed names in the index". Since > > >>> the format has been stable for so long, almost all versions of Git > > >>> in use today understand version 4, removing one barrier to upgrade > > >>> -- that someone may want to downgrade and needs a working repo. > > >> What about alternative implementations, like JGit, libgit2, etc.? > > > Speaking of libgit2, we are able to read and write index v4 since > > > commit c1b370e93 > > > > This is a good point, Szeder. > > > > Patrick: I'm glad LibGit2 is up-to-date with index formats. > > > > Unfortunately, taking a look (for the first time) at the JGit code > > reveals that they don't appear to have v4 support. In > > org.eclipse.jgit/src/org/eclipse/jgit/dircache/DirCache.java, the > > DirCache.readFrom() method: lines 488-494, I see the following snippet: > > > > final int ver = NB.decodeInt32(hdr, 4); > > boolean extended = false; > > if (ver == 3) > > extended = true; > > else if (ver != 2) > > throw new > > CorruptObjectException(MessageFormat.format( > > JGitText.get().unknownDIRCVersion, Integer.valueOf(ver))); > > > > It looks like this will immediately throw with versions other than 2 or 3. > > > > I'm adding Jonathan Nieder to CC so he can check with JGit people about > > the impact of this change. > > JGit is used both on the server (which doesn't use index/staging area) > as well as client side as e.g. an Eclipse integration, which would > very much like to use the index. > > Adding Matthias Sohn as well, who is active in JGit and cares > more about the client side than Googlers who only make use > of the server side part of JGit. thanks for the heads up, in fact JGit does not yet support index version 4. I will look into this. -Matthias
