Ignore merge commits when looking at the pristine-tar branch

When there is a merge commit in this branch, we currently get the
warning:

  gbp:warning: Unknown compression type of Merge branch 'pristine-tar' into 'pristine-tar', assuming gzip

because we're grepping the commit logs to find out the compression type
of the tarballs in there.

For now, we can just use `git log ... --no-merges' to not see these
commits.

Signed-off-by: Guido Günther <agx@sigxcpu.org>
Closes: #906331

1 files changed, 3 insertions, 1 deletions

diff --git a/gbp/git/repository.py b/gbp/git/repository.py
index 1fc92ee9..827bf17b 100644
--- a/gbp/git/repository.py
+++ b/gbp/git/repository.py
@@ -1645,7 +1645,7 @@ class GitRepository(object):
             raise GitRepositoryError("can't get %s: %s" % (id, stderr.decode().rstrip()))
         return obj
 
-    def grep_log(self, regex, since=None):
+    def grep_log(self, regex, since=None, merges=True):
         """
         Get commmits matching I{regex}
 
@@ -1655,6 +1655,8 @@ class GitRepository(object):
         @type since: C{str}
         """
         args = ['--pretty=format:%H']
+        if not merges:
+            args.append("--no-merges")
         args.append("--grep=%s" % regex)
         if since:
             args.append(since)