Re: [gentoo-portage-dev] [PATCH 3/3] portage.dbapi.vartree: Support exclusions in INSTALL_MASK

[Zac Medico]

On 05/21/2016 11:56 PM, Michał Górny wrote:
> Allow INSTALL_MASK patterns to start with '-' to indicate that
> a specific match is to be excluded from being masked. In this case,
> the last matching pattern determines whether the file is actually
> filtered out or kept.
> ---
>  pym/portage/dbapi/vartree.py | 10 ++++++----
>  1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/pym/portage/dbapi/vartree.py b/pym/portage/dbapi/vartree.py
> index 8e5ac43..d02d850 100644
> --- a/pym/portage/dbapi/vartree.py
> +++ b/pym/portage/dbapi/vartree.py
> @@ -3690,19 +3690,21 @@ class dblink(object):
>  	def _is_install_masked(self, relative_path):
>  		ret = False
>  		for pattern in self.settings.install_mask:
> +			# if pattern starts with -, possibly exclude this path
> +			pat_res = not pattern.startswith('-')
> +			if not pat_res:
> +				pattern = pattern[1:]
>  			# absolute path pattern
>  			if pattern.startswith('/'):
>  				# match either exact path or one of parent dirs
>  				# the latter is done via matching pattern/*
>  				if (fnmatch.fnmatch(relative_path, pattern[1:])
>  						or fnmatch.fnmatch(relative_path, pattern[1:] + '/*')):
> -					ret = True
> -					break
> +					ret = pat_res
>  			# filename
>  			else:
>  				if fnmatch.fnmatch(os.path.basename(relative_path), pattern):
> -					ret = True
> -					break
> +					ret = pat_res
>  		return ret
>
>  	def treewalk(self, srcroot, destroot, inforoot, myebuild, cleanup=0,
>

In order to implement this with pre-compiled patterns, we can use a
separate regular expression to represent all of the exclusions.
-- 
Thanks,
Zac