Re: gitignore + commit with excludes = bug
- From
Matheus Tavares <matheus.bernardino@usp.br>
- Date
- May 4, 2021, 14:06 UTC
- Message-ID
- <789bcc9cd074cb94f706b9d432e29b52bf6a33c3.1620134775.git.matheus.bernardino@usp.br>
- In-Reply-To
- <e4c3d482-03b4-141c-e47b-cb3e175da3ab@iee.email>
Hi, Paul and Philip
On Tue, May 4, 2021 at 9:55 AM Philip Oakley <philipoakley@iee.email> wrote:
Show 42 quoted lines
> > Hi Paul, > > On 01/05/2021 19:37, Paul Jackson wrote: > > Hello, > > > > I stumbled upon what I believe is a bug in git. > > See the following reproduction steps: > > > > mkdir test > > cd test > > git init > > echo 1 > ignored > > echo 1 > not-ignored > > echo ignored > .gitignore > > git add -A -- ':!ignored' || echo 'ERROR!!!' > > > > In these steps, I ignore the "ignored" file twice - first time in > > .gitignore, and second time in the "git add" command. I didn't expect > > this to be a problem, but I'm getting the following error message: > > > > The following paths are ignored by one of your .gitignore files: > > ignored > > > > It looks as if git thinks I wanted to include, not exclude "ignored" > > in "git add". > I was intrigued by this. The man pages can be hard to decipher, and it > may be an 'as designed' feature, but still not intuitive > > It took a while to find the relevant parts of the man pages. > > The `-A` option of `add` is under > https://git-scm.com/docs/git-add#Documentation/git-add.txt---no-ignore-removal > which has caveats for whether a pathspec is given. > > The `exclude` magic pathspec is under > https://git-scm.com/docs/gitglossary#Documentation/gitglossary.txt-exclude > and again has caveats and a double negative regarding whether the > `exclude` pathspec counts as a path spec. > > I _think_ that it is saying that the `exclude` pathspec is ignored for > the purpose of the `-A` (all) condition for git add.
Hmm, I think the issue is not really related to `-A`. In fact, if we reproduce Paul's original example without `-A`, we still get the warning.
The problem seems to be at `dir.c:exclude_matches_pathspec()`, which creates the list of ignored files that is later used by `git add` to presented the "The following paths are ignored..." warning.
This function ignores the `exclude` magic, so a path 'x' incorrectly matches both ':x' and ':!x'. And thus, we end up warning the user about 'x' being ignored even when the user had ran `git add ':!x'`.
I think something like this, might solve the problem:
diff --git a/dir.c b/dir.c index 3474e67e8f..165ca6a543 100644 --- a/dir.c +++ b/dir.c @@ -2042,6 +2042,25 @@ static int exclude_matches_pathspec(const char *path, int pathlen, const struct pathspec_item *item = &pathspec->items[i]; int len = item->nowildcard_len; + if (!(item->magic & PATHSPEC_EXCLUDE)) + continue; + + if (len == pathlen && + !ps_strncmp(item, item->match, path, pathlen)) + return 0; + if (len > pathlen && + item->match[pathlen] == '/' && + !ps_strncmp(item, item->match, path, pathlen)) + return 0; + } + + for (i = 0; i < pathspec->nr; i++) { + const struct pathspec_item *item = &pathspec->items[i]; + int len = item->nowildcard_len; + + if (item->magic & PATHSPEC_EXCLUDE) + continue; + if (len == pathlen && !ps_strncmp(item, item->match, path, pathlen)) return 1; --- I had to split the original loop into two and handle the `exclude` pathspecs first because we cannot let the original loop return early when one of the `non-exclude` pathspecs matches the path. Otherwise, we would still incorrectly warn the user on executions like `git add ignored ':!ignored'`. (We might also want to extract the matching part to its own function to avoid repeating this code on the two loops.)