On Tue, May 4, 2021 at 7:10 AM Matheus Tavares <matheus.bernardino@xxxxxx> wrote: > > Hi, Paul and Philip > > On Tue, May 4, 2021 at 9:55 AM Philip Oakley <philipoakley@iee.email> wrote: > > > > 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; > --- Thanks for tracking this down. Your analysis and patch look correct to me, but perhaps we could simplify the code a bit. Instead of looping twice, perhaps insert the following code above the if-checks: + /* + * We can have a bunch of exclusion rules: + * .gitignore + * *.log + * !settings.log + * and we're trying to see if the path matches one of these, + * but note that the last one is a "negated exclusion rule", + * for the excludes to match this pathspec, it needs to not + * match the negated exclusion. + */ + int retval = (item->magic & PATHSPEC_EXCLUDE) ? 0 : 1; and then change all the "return 1" statements to "return retval". Thoughts? > > 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.)
