Fix #219

2 files changed, 16 insertions, 3 deletions

diff --git a/setuptools_scm/hg.py b/setuptools_scm/hg.py
index 9322fb3..0ba1774 100644
--- a/setuptools_scm/hg.py
+++ b/setuptools_scm/hg.py
@@ -8,8 +8,14 @@ FILES_COMMAND = 'hg locate -I .'
 def _hg_tagdist_normalize_tagcommit(root, tag, dist, node):
     dirty = node.endswith('+')
     node = 'h' + node.strip('+')
-    revset = ("(branch(.) and tag({tag!r})::. and file('re:^(?!\.hgtags).*$')"
-              " - tag({tag!r}))").format(tag=tag)
+
+    # Detect changes since the specified tag
+    revset = ("(branch(.)"  # look for revisions in this branch only
+              " and tag({tag!r})::."  # after the last tag
+              # ignore commits that only modify .hgtags and nothing else:
+              " and (merge() or file('re:^(?!\.hgtags).*$'))"
+              " and not tag({tag!r}))"  # ignore the tagged commit itself
+              ).format(tag=tag)
     if tag != '0.0':
         commits = do(['hg', 'log', '-r', revset, '--template', '{node|short}'],
                      root)
diff --git a/testing/test_mercurial.py b/testing/test_mercurial.py
index 6df3cc0..1d91444 100644
--- a/testing/test_mercurial.py
+++ b/testing/test_mercurial.py
@@ -134,6 +134,13 @@ def test_version_bump_before_merge_commit(wd):
     assert wd.version.startswith('1.1.dev1+')
 
 
+@pytest.mark.issue(219)
+@pytest.mark.usefixtures("pre_merge_commit_after_tag")
+def test_version_bump_from_merge_commit(wd):
+    wd.commit()
+    assert wd.version.startswith('1.1.dev3+')  # issue 219
+
+
 @pytest.mark.usefixtures("version_1_0")
 def test_version_bump_from_commit_including_hgtag_mods(wd):
     """ Test the case where a commit includes changes to .hgtags and other files
@@ -144,4 +151,4 @@ def test_version_bump_from_commit_including_hgtag_mods(wd):
     wd(wd.add_command)
     assert wd.version.startswith('1.1.dev1+')  # bump from dirty version
     wd.commit()  # commits both the testfile _and_ .hgtags
-    assert wd.version.startswith('1.1.dev2+')
\ No newline at end of file
+    assert wd.version.startswith('1.1.dev2+')