Re: Does changing filename case breaks git's rename heuristic?

[Dan Loewenherz <dloewenherz@gmail.com>]

On Fri, Aug 27, 2010 at 1:00 AM, Michael J Gruber
<git@drmicha.warpmail.net> wrote:
> Dan Loewenherz venit, vidit, dixit 27.08.2010 06:57:
>> Hi all,
>>
>> I may be mistaking a design decision as a bug, but I wanted to throw
>> this out to the list to make sure. I think that re-enacting it will be
>> the best way to explain it.
>>
>> $ mkdir test
>> $ cd test
>> $ git init
>> $ cat > readme
>> This is a test file.
>> ^D
>> $ git commit -am "first commit"
>> [master (root-commit) fae0d05] first commit
>>  1 files changed, 1 insertions(+), 0 deletions(-)
>
> ? You have not added any file, so git won't commit anything (not even
> with -a). The above can't be a complete transcription. I assume you've
> added readme with the content above.

Yep, that was my mistake. I left out 'git add readme'.

>
>>
>> For personal reasons, I now want readme to be uppercase.
>>
>> $ mv readme README
>
> Here's where using "git mv" would have been the easier choice, followed
> by commit.

I agree. The instance where this actually occurred was that I had
received an updated binary file to put into my repository. icon.png ->
Icon.png. I suppose I could've run 'git mv' but I didn't realize what
would happen if I didn't!

>
>> $ cat > README
>> This is the revised README.
>
> Renaming and changing the content completely in one step will always
> trip up git's rename detection. You should rename, commit, change,
> commit, unless the change affects a small portion of the file only.

Agreed.

>
>> $ git status -sb
>> ## master
>>  M readme
>
> Again, this can't be a complete transcript. The above would lead to
>
>  D readme
> ?? README

This is where I didn't botch up the transcript, and where I was
actually surprised at what was going on. I'll insert a full one at the
bottom of this email that can actually be run to get the same results.

>
>> $ git add README
>> $ git status -sb
>> ## master
>>  M readme
>>
>> At this point, I'm thinking that git is confused. Even though I've
>
> Are you possibly using a case-challenged file system? Is this maybe on a
> Mac with HFS or Win with NTFS?

I'm using a Mac with a journaled filesystem and Git version 1.7.2.1.

>
> Michael
>

Transcript

dan ~ $ mkdir test
dan ~ $ cd test/
dan test $ git init
Initialized empty Git repository in /Users/dan/test/.git/
dan test (master #) $ cat > readme
This is a test file.
dan test (master #%) $ git add readme
dan test (master #) $ git ci -m "first commit"
[master (root-commit) 3237fcb] first commit
 1 files changed, 1 insertions(+), 0 deletions(-)
 create mode 100644 readme
dan test (master) $ mv readme README
dan test (master) $ cat > README
This is the revised README.
dan test (master *) $ git s
## master
 M readme
dan test (master *) $ git add README
dan test (master *) $ git s
## master
 M readme
dan test (master *) $ git add readme
dan test (master +) $ git s
## master
M  readme
dan test (master +) $ git ci -m "change filename"
[master 587f3f8] change filename
 1 files changed, 1 insertions(+), 1 deletions(-)
dan test (master) $ git --version
git version 1.7.2.1