Brandon Williams <bmw...@google.com> writes: >> Again, what do we have in "name" and "item" at this point? If we >> have a submodule at "sub/" and we are checking a pathspec element >> "sub/dir1/*", what is the non-wildcard part of the pathspec and what >> is the "string"? Aren't they "sub/dir1/" and "sub/" respectively, >> which would not pass ps_strncmp() and produce a (false) negative? > > item will be the pathspec_item struct that we are trying to match against.
... which would mean "sub/dir1/" in the above example (which is followed by '*' that is wildcard). > name will be the file we are trying to match, which should already have the > 'prefix' cut off (this is the prefix that is used as an optimization > in the common > case, which isn't used in the submodule case). ... which would be "sub/" in the above example, because we disable the common-prefix optimization. So in short, the answer to the last questions in the first quoted paragraph are yes, yes, and "no they do not pass ps_strncmp()"? >> I am starting to have a feeling that the best we can do in this >> function safely is to see if prefix (i.e. the constant part of the >> pathspec before the first wildcard) is long enough to cover the >> "name" and if "name" part [matches or does not match] ... >> If these two checks cannot decide, we may have to be pessimistic and >> say "it may match; we don't know until we descend into it". >> ... >> So I would think we'd be in the business of counting slashes in the >> name (called "string" in this function) and the pathspec, while >> noticing '*' and '**' in the latter, and we may be able to be more >> precise, but I am not sure how complex the end result would become. > > I agree, I'm not too sure how much more complex the logic would need > to be to handle > all matters of wildcard characters. We could initially be more > lenient on what qualifies as > a match and then later (or in the near future) revisit the wildmatch > function (which is complex) > and see if we can add better matching capabilities more suited for > submodules while at the > same time fixing that bug discussed above. I think it is reasonable to start a function that is meant to never have false negatives pessimistic and return "might match" from it when in doubt. Thanks.
