Hi wh
On 14/04/2019 02:59, wh wrote:
Thanks for the info about the upcoming "precious" attribute. Looks useful.
I didn't get the impression that Git normally overwrites ignored
files. I ran some more experiments:
git rebase FETCH_HEAD # bails
git rebase -i FETCH_HEAD # overwrites
git merge FETCH_HEAD # bails
git reset --keep FETCH_HEAD # bails
git reset --merge FETCH_HEAD # bails
git checkout FETCH_HEAD # overwrites
# without feature 2 locally:
git merge FETCH_HEAD # overwrites, fast-forwards
git merge --no-ff FETCH_HEAD # bails
I've had a look at the rebase -i code and I think it only overwrites
ignored files when it is fast-forwarding. This matches what merge does
when fast-forwarding but I'm not convinced either of them should be
doing this by default (I think checkout doing it is probably asking for
trouble), as you point out most operations preserve ignored files. When
pull fast-forwards it does not overwrite ignored files.
Both checkout and merge have an undocumented --overwrite-ignore option
which is on by default. Checkout and fast-forward merges overwriting
ignored files dates back a long way to commit 1127148089 ("Loosen
"working file will be lost" check in Porcelain-ish", 2006-12-04). There
does not seem to have been much discussion of changing the semantics of
ignored files around the patches that implemented this [1,2]. There is a
brief mention of doing it in this thread [3] but no one seems to comment
on the idea as far as I can see. Before this change ignored files were
just ignored by status and add but otherwise treated like any other
untracked file.
I'll put a patch together to fix rebase -i, I'd like to see the defaults
for merge and checkout changed but I'm not sure that would be popular.
It does seem like surprising behavior though when most operations try to
preserve untracked files.
Best Wishes
Phillip
[1]
https://public-inbox.org/git/7vlklnkv39.fsf@xxxxxxxxxxxxxxxxxxxxxxxx/T/#u
[2]
https://public-inbox.org/git/7vbqmjkuzd.fsf@xxxxxxxxxxxxxxxxxxxxxxxx/T/#u
[3]https://public-inbox.org/git/Pine.LNX.4.64.0610081657400.3952@xxxxxxxxxxx/
On Fri, Apr 12, 2019 at 9:30 AM Phillip Wood <phillip.wood123@xxxxxxxxx> wrote:
Hi
On 12/04/2019 00:56, wh wrote:
I'm using git 2.20.1 from Debian. Git is usually careful not to
overwrite untracked files, including ignored files.
Git normally overwrites ignored files, so I think in your example rebase
-i is working as expected, I'm surprised that the am based rebase does
not overwrite the ignored file. There has been some discussion about
introducing 'precious' files that are ignored but protected in the same
way as untracked files [1].
Best Wishes
Phillip
[1] https://public-inbox.org/git/20190409102649.22115-1-pclouds@xxxxxxxxx/
But interactive
rebase doesn't detect this (non-interactive rebase works fine).
Reproduction:
-----
#!/bin/sh
mkdir upstream
cd upstream
git init
echo 1 >feature-1
git add feature-1
git commit -m "feature 1"
cd ..
git clone upstream local
cd local
# write some tools for our own convenience
echo ours >tools
echo /tools >>.git/info/exclude
# start working on a feature
git checkout -b f2
echo wip >feature-2
git add feature-2
git commit -m "wip"
cd ../upstream
# official tools are available
echo theirs >tools
git add tools
git commit -m "tools"
cd ../local
git fetch ../upstream master
# this would be okay
#git rebase FETCH_HEAD
# problem: overwrites tools silently
GIT_EDITOR=true git rebase -i FETCH_HEAD
cat tools
-----
Expected: `git rebase -i` fails because it would have to overwrite the
untracked "tools" file. Contents of tools file remains `ours`.
Actual: Contents of tools file becomes `theirs`.
