rebase failure if commit message looks like a patch

I have found a strange behaviour of "git rebase", present in following versions:

@@ -1,5 +1,5 @@
-1
+1 - upstream
 2
 3
 4
-5
+5 - feature
------------------ bad-commit-message } ---------------

Following shell script reproduces the bug for me:

------------------ show-bug.sh { ---------------
#!/bin/bash
rm -rf r # clean-up
mkdir r # repo dir
cd r
git init
cd ..
cp a0 r/a
cd r
git add a
git ci -m "initial addition of a0"
git br feature
git co feature
cd ..
cp a1 r/a
cd r
git add a
## no bug
#git ci -m "changeset a1 - feature added"
# bug
git ci -F ../bad-commit-message
git co master
cd ..
cp a2 r/a
cd r
git add a
git ci -m "changeset a2 - upstream revision"
git co feature
git rebase master
------------------ show-bug.sh } ---------------

produces the error on final rebase attempt:

First, rewinding head to replay your work on top of it...
Applying: changeset a1 - feature added
error: r/a: does not exist in index
fatal: sha1 information is lacking or useless (r/a).
Repository lacks necessary blobs to fall back on 3-way merge.
Cannot fall back to three-way merge.
Patch failed at 0001.

When you have resolved this problem run "git rebase --continue".
If you would prefer to skip this patch, instead run "git rebase --skip".
To restore the original branch and stop rebasing run "git rebase --abort".

In case one uses
# no bug
git ci -m "changeset a1 - feature added"
instead of
# bug
git ci -F ../bad-commit-message

The final rebase succeded !

Content of other files:

---------------- a0 { -------------------
1
2
3
4
5
---------------- a0 } -------------------

---------------- a1 { -------------------
1
2
3
4
5 - feature
---------------- a1 } -------------------

---------------- a2 { -------------------
1 - upstream
2
3
4
5
---------------- a2 } -------------------

-- 
Anton

Johannes Schindelin· Jan 27, 2009, 18:15 UTC · re: Anton · lore

Re: rebase failure if commit message looks like a patch

Hi,

On Tue, 27 Jan 2009, Anton wrote:

> I have found a strange behaviour of "git rebase", present in following 
> versions: