diff -r 03708c680eca Lib/unittest/case.py
--- a/Lib/unittest/case.py	Wed Feb 03 07:52:06 2016 +0000
+++ b/Lib/unittest/case.py	Tue Feb 02 22:19:54 2016 +0530
@@ -1183,10 +1183,11 @@
                 len(second) > self._diffThreshold):
                 self._baseAssertEqual(first, second, msg)
             firstlines = first.splitlines(keepends=True)
+            firstlines[len(firstlines)-1] = self._appendNewLineChar(
+                firstlines[len(firstlines)-1])
             secondlines = second.splitlines(keepends=True)
-            if len(firstlines) == 1 and first.strip('\r\n') == first:
-                firstlines = [first + '\n']
-                secondlines = [second + '\n']
+            secondlines[len(secondlines)-1] = self._appendNewLineChar(
+                secondlines[len(secondlines)-1])
             standardMsg = '%s != %s' % _common_shorten_repr(first, second)
             diff = '\n' + ''.join(difflib.ndiff(firstlines, secondlines))
             standardMsg = self._truncateMessage(standardMsg, diff)
@@ -1302,6 +1303,11 @@
             msg = self._formatMessage(msg, standardMsg)
             raise self.failureException(msg)
 
+    def _appendNewLineChar(self, line):
+        if line.rstrip('\r\n') == line:
+            return line + '\n'
+        return line
+
 
     def _deprecate(original_func):
         def deprecated_func(*args, **kwargs):