[bitbake-devel] [PATCH] fetch2/git: Add workaround for clone using alternates problem

[Richard Purdie]

To quote my report of this to the git mailing list:
"""
    
    I have a problem with git clone commands using alternates failing by
    mixing up different repositories. I have a situation where I could end
    up with both:
    
    /srv/mirrors/repo
    /srv/mirrors/repo.git
    
    as bare clones.
    
    I then try cloning "repo" with alternates with the command:
    
    $ git clone -s -n /srv/mirrors/repo /tmp/foo
    Cloning into /tmp/foo...
    done.
    
    $ cat /tmp/foo/.git/objects/info/alternates
    /srv/mirrors/repo.git/objects
    
    Note how I'm now referencing repo.git, not repo. This doesn't work as
    expected giving some very bizarre results when actually using the
    repository.
    
    I appreciate this is a rather bizarre corner case but its one that is
    breaking the build system I work with. Ideally people would use a
    consistent URL for the same repository but we have an example where they
    haven't and this really shouldn't break like this.
    
    Looking at the code, the cause seems to be
    
    clone.c:get_repo_path():
            static char *suffix[] = { "/.git", ".git", "" };
    
    since its looking in order for:
     repo/.git (fails)
     repo.git (suceeds, incorrect)
     repo (never looked at)
    
    I'm not sure what would break if that order were to change, swapping the
    last two options.
    
    I can "force" the issue by running:
    
    git clone -s -n /srv/mirrors/repo/ /tmp/foo
    
    but this results in the slightly odd looking:
    
    $ cat /tmp/foo/.git/objects/info/alternates
    
    /srv/mirrors/repo//objects
    
    which does at least work.
"""
    
This patch adds the trailing slash to ensure the correct repository is
referenced at the expense of some ugliness in the alternates file.
    
Signed-off-by: Richard Purdie <richard.purdie at linuxfoundation.org>

diff --git a/lib/bb/fetch2/git.py b/lib/bb/fetch2/git.py
index d833714..fb0260a 100644
--- a/lib/bb/fetch2/git.py
+++ b/lib/bb/fetch2/git.py
@@ -220,7 +220,7 @@ class Git(FetchMethod):
         if os.path.exists(destdir):
             bb.utils.prunedir(destdir)
 
-        runfetchcmd("git clone -s -n %s %s" % (ud.clonedir, destdir), d)
+        runfetchcmd("git clone -s -n %s/ %s" % (ud.clonedir, destdir), d)
         if not ud.nocheckout:
             os.chdir(destdir)
             if subdir != "":