[PATCH] bitbake/fetch2/git: Don't set the branch name to None, that makes no sense

[Richard Purdie <richard.purdie@linuxfoundation.org>]

With floating revisions and no specified branch, the fetcher could fail
with some obtuse errors. This was due to the branch name being set to None
which makes no sense. This patch reworks some conditions to avoid this.

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
---
diff --git a/bitbake/lib/bb/fetch2/git.py b/bitbake/lib/bb/fetch2/git.py
index bcc0da5..5efdfa9 100644
--- a/bitbake/lib/bb/fetch2/git.py
+++ b/bitbake/lib/bb/fetch2/git.py
@@ -123,7 +123,8 @@ class Git(FetchMethod):
         for name in ud.names:
             # Ensure anything that doesn't look like a sha256 checksum/revision is translated into one
             if not ud.revisions[name] or len(ud.revisions[name]) != 40  or (False in [c in "abcdef0123456789" for c in ud.revisions[name]]):
-                ud.branches[name] = ud.revisions[name]
+                if ud.revisions[name]:
+                    ud.branches[name] = ud.revisions[name]
                 ud.revisions[name] = self.latest_revision(ud.url, ud, d, name)
 
         gitsrcname = '%s%s' % (ud.host.replace(':','.'), ud.path.replace('/', '.'))