From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Shawn O. Pearce" <spearce@spearce.org>
Subject: Re: Why is TreeWalk.forPath(...) returning null
Date: Wed, 12 Nov 2008 14:42:36 -0800
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References: <491B579E.6050408@wellfleetsoftware.com>
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To: Farrukh Najmi <farrukh@wellfleetsoftware.com>
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Farrukh Najmi <farrukh@wellfleetsoftware.com> wrote:
>
> My "git status" command shows:
>
> # On branch master
> # Changed but not updated:
> #   (use "git add <file>..." to update what will be committed)
> #
> #    modified:   xml/minDB/SubmitObjectsRequest_CMSScheme.xml
>
> The file above was committed and then modified. I want to use jgit to  
> find the comitted version of that file.
>
> When I do the following code I get a null treeWalk? Why is that? What  
> should I specify for path instead?
>
>            String path = "xml/minDB/SubmitObjectsRequest_CMSScheme.xml";
>            String versionName = Constants.HEAD;
>
>            Commit commit = repository.mapCommit(versionName);
>
>            if (commit == null) {
>                log.trace("Did not find Commit. versionName:" +  
> versionName);
>            } else {
>                ObjectId[] ids = {commit.getTree().getId()};
>                TreeWalk treeWalk = TreeWalk.forPath(repository, path, ids);
>            }

Huh.  That should have worked.

TreeWalk.forPath returns null if the path doesn't get found.  So
it sounds like jgit isn't matching the path.  Its a pretty simple
operation, I'm not sure why its failing here.  I'd run it through
a debugger to try and see why the TreeWalk didn't match your path.

Your code is logically the same as:

  git rev-parse HEAD:$path

so it should find the blob if Git would have found it.

-- 
Shawn.