Re: gitignore: negating path patterns

[Michael J Gruber <michaeljgruber+gmane@fastmail.fm>]

Kevin Ballard venit, vidit, dixit 24.05.2008 00:44:
> On May 23, 2008, at 12:52 AM, Michael J Gruber wrote:
> 
>> Kevin Ballard venit, vidit, dixit 23.05.2008 02:23:
>>> On May 21, 2008, at 7:52 AM, Michael J Gruber wrote:
>>>> Hi there
>>>>
>>>> It seems that negating path patterns in gitignore doesn't work, or I
>>>> don't understand it (or both). With the attached script, git status
>>>> (1.5.5.1) reports "dir/a" as new and "dir/b" as untracked. I would
>>>> rather expect it to report "dir/c" as untracked also.
>>>>
>>>> It seems that "!b" matches to include "dir/b" (reverting the  
>>>> exclusion
>>>> "*" as expected), whereas "!dir/" does not match to include "dir/c".
>>>>
>>>> What's going on here?
>>> "dir/" will not match anything, because paths are compared without   
>>> trailing slashes. Try "!dir".
>> I am sorry, but this is plain wrong, at least if "man gitignore" is  
>> right (see below). "!dir" would match files whose name (pathname  
>> without leading directory name) matches "dir" (i.e.: is dir) and  
>> exclude those from exclusion (include them).
>>
>> Also, replacing "!dir/" by "!dir" in my test script does not change  
>> the result. In fact, for "!dir" the result is as expected and  
>> documented, just for "!dir/" I would expect something else.
>>
>> So, thanks for trying to help, although reading the manual or  
>> testing your advice before would be appreciated even more. ;)
>>
>> Michael
>>
>> From man gitignore:
>>
>> If the pattern ends with a slash, it is removed for the purpose of  
>> the following description, but it would only find a match with a  
>> directory. In other words, foo/ will match a directory foo and paths  
>> underneath it, but will not match a regular file or a symbolic link  
>> foo (this is consistent with the way how pathspec works in general  
>> in git).
> 
> Ahh, the behavior changed in 1.5.5. Pre-1.5.5, if a path ended in a  
> slash, it would never match anything.
> 
> In any case, the problem is the * pattern. Here's what happens:
> 
> At /, the * is evaluated and ignores everything. The !dir/ is  
> evaluated and unignores dir. The !b is evaluated and matches nothing.
> AT /dir, the * is evaluated and ignores everything. The !dir/ is  
> evaluated and matches nothing. The !b is evaluated and unignores b.
> 
> So the problem is the * is recursively applying to the subdirectories.  
> To fix this, use /* as the pattern.

You're right, that's how it works now. Thanks a bunch! Nothings beats 
"using the s/force/source/".

I find this behaviour highly confusing for someone going by 
"gitgnore(5)". I'll try and submit a documentation fix as a first 
attempt at contributing back.

Michael