Test and fix Version.truncate()

Calling `Version.truncate("build")` should return a fresh instance, as
caught in #141

Closes: #141, #142

1 files changed, 8 insertions, 1 deletions

diff --git a/semantic_version/base.py b/semantic_version/base.py
index 777c27a..1c10155 100644
--- a/semantic_version/base.py
+++ b/semantic_version/base.py
@@ -181,7 +181,14 @@ class Version(object):
     def truncate(self, level='patch'):
         """Return a new Version object, truncated up to the selected level."""
         if level == 'build':
-            return self
+            return Version(
+                major=self.major,
+                minor=self.minor,
+                patch=self.patch,
+                prerelease=self.prerelease,
+                build=self.build,
+                partial=self.partial,
+            )
         elif level == 'prerelease':
             return Version(
                 major=self.major,