gbp.deb.changelog: Allow to parse out changes from a specific version

We don't iterate over all individual sections but rather let
dpkg-parsechangelog do the hard work.

2 files changed, 28 insertions, 3 deletions

diff --git a/gbp/deb/changelog.py b/gbp/deb/changelog.py
index 42fcb571..ac867a93 100644
--- a/gbp/deb/changelog.py
+++ b/gbp/deb/changelog.py
@@ -91,9 +91,9 @@ class ChangeLog(object):
             self._read()
         self._parse()
 
-    def _parse(self):
-        """Parse a changelog based on the already read contents."""
-        cmd = subprocess.Popen(['dpkg-parsechangelog', '-l-'],
+    def _run_parsechangelog(self, options=None):
+        options = options if options is not None else []
+        cmd = subprocess.Popen(['dpkg-parsechangelog', '-l-'] + options,
                                stdin=subprocess.PIPE,
                                stdout=subprocess.PIPE,
                                stderr=subprocess.PIPE)
@@ -101,6 +101,11 @@ class ChangeLog(object):
         if cmd.returncode:
             raise ParseChangeLogError("Failed to parse changelog. "
                                       "dpkg-parsechangelog said:\n%s" % (errors, ))
+        return output
+
+    def _parse(self):
+        """Parse a changelog based on the already read contents."""
+        output = self._run_parsechangelog()
         # Parse the result of dpkg-parsechangelog (which looks like
         # email headers)
         cp = email.message_from_string(output)
@@ -310,3 +315,6 @@ class ChangeLog(object):
         """
         self.spawn_dch(msg=msg, newversion=True, version=version, author=author,
                        email=email, distribution=distribution, dch_options=dch_options)
+
+    def get_changes(self, since='0~'):
+        return self._run_parsechangelog(['-v%s' % since, '-SChanges'])
diff --git a/tests/doctests/test_Changelog.py b/tests/doctests/test_Changelog.py
index 9525e76d..cddf5ae7 100644
--- a/tests/doctests/test_Changelog.py
+++ b/tests/doctests/test_Changelog.py
@@ -223,6 +223,23 @@ def test_parse_sections():
     """
 
 
+def test_get_changes():
+    """
+    Test if we can get changes
+
+    Methods tested:
+         - L{gbp.deb.changelog.ChangeLog.__init__}
+         - L{gbp.deb.changelog.ChangeLog.get_changes}
+
+    >>> import gbp.deb.changelog
+    >>> cl = gbp.deb.changelog.ChangeLog(cl_debian)
+    >>> len(cl.get_changes().split('\\n'))
+    19
+    >>> len(cl.get_changes('0.5.31').split('\\n'))
+    7
+    """
+
+
 def test_add_section():
     """
     Test if we can add a section to an existing changelog