Re: [OSSTEST PATCH] build_clone: git clean newly cloned trees

[Ian Campbell <ian.campbell@citrix.com>]

On Thu, 2015-10-29 at 16:01 +0000, Andrew Cooper wrote:
> On 29/10/15 15:57, Ian Jackson wrote:
> > This may seem redundant, however:
> > 
> > git does not track empty directories.  So it can happen that a
> > directory is created as part of `git clone', but is empty in the
> > revision switched to with `git checkout'.
> > 
> > In this situation, the tree we are going to build ought not to contain
> > this directory, because that directory will not (in general) be
> > produced, eg when the revision being switched to becomes master.
> > 
> > We can use git clean to produce a working tree whose contents -
> > including the presence or absence of empty directories - depends only
> > on the commit we are trying to check out, and not on the previous
> > states of the git history or working tree.
> > 
> > For example, if a directory is made empty (ie, deleted, since git does
> > not distinguish) in xen.git#staging, osstest's clones of
> > xen.git#master will produce the directory, but `git checkout' of
> > staging won't delete it.  If the xen.git build system mistakenly
> > depends on this directory, we won't detect this until the deletion
> > reaches master.  This situation actually occurred with xen.git#598e97f
> > "tools/python: remove broken xl binding" (fixed in b261366f).
> > 
> > Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
> > CC: Andrew Cooper <andrew.cooper3@citrix.com>
> 
> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>

Acked-by: Ian Campbell <ian.campbell@citrix.com>