Merge "Keep scanning master branch after first shared commit"

releasenotes/notes/keep-scanning-past-branchpoint-61f72023c32cf0b3.yaml

@@ -0,0 +1,10 @@
+---
+features:
+  - |
+    If no earliest version is provided for a branch, reno will scan commits
+    on the branch in reverse order, attempting to find a common ancestor
+    with the master branch. Once found, the last common commit - the branch
+    point - is checked for a tag. Previously, if no tag was found, reno
+    would stop scanning. This was problematic for instances where a branch
+    was not created at the tagged commit but rather some commits later.
+    Reno will now continue scanning until it finds a tag.

reno/scanner.py

@@ -660,13 +660,13 @@ class Scanner(object):
                     c.commit.sha().hexdigest().encode('ascii'))
                 if tags:
                     return tags[-1]
-                else:
-                    # Naughty, naughty, branching without tagging.
-                    LOG.info(
-                        ('There is no tag on commit %s at the base of %s. '
-                         'Branch scan short-cutting is disabled.'),
-                        c.commit.sha().hexdigest(), branch)
-                    return None
+
+        # Naughty, naughty, branching without tagging.
+        LOG.info(
+            'There is no tag on commit %s at the base of %s. '
+            'Branch scan short-cutting is disabled.',
+            c.commit.sha().hexdigest(), branch,
+        )
         return None
 
     def _topo_traversal(self, branch):

reno/tests/test_scanner.py

@@ -1269,10 +1269,19 @@ class BranchBaseTest(Base):
         self.repo.git('tag', '-d', '2.0.0')
         self._add_notes_file('slug4')
         self.repo.git('checkout', 'master')
-        self.assertIsNone(
-            self.scanner._get_branch_base('not-master')
+        self.assertEqual(
+            '1.0.0',
+            self.scanner._get_branch_base('not-master'),
         )
 
+    def test_no_tags(self):
+        # remove all tags from before the branch
+        self.repo.git('tag', '-d', '2.0.0')
+        self.repo.git('tag', '-d', '1.0.0')
+        self._add_notes_file('slug4')
+        self.repo.git('checkout', 'master')
+        self.assertIsNone(self.scanner._get_branch_base('not-master'))
+
 
 class BranchTest(Base):