Fixed test case: test__escape_preserves_unicode_subclasses in test_renderengine.py.

pystache/renderengine.py

@@ -389,17 +389,21 @@ class Template(object):
     def partial(self, name, context=None):
         return context.partial(name)
 
-    def escape_tag_function(self, name):
-        get_literal = self.literal_tag_function(name)
-        def func(context):
-            u = get_literal(context)
-            u = self.escape(u)
-            return u
-        return func
+    def _get_string_value(self, context, tag_name):
+        """
+        Get a value from the given context as a basestring instance.
 
-    def literal_tag_function(self, name):
-        def func(context):
-            val = context.get(name)
+        """
+        val = context.get(tag_name)
+
+        # We use "==" rather than "is" to compare integers, as using "is"
+        # relies on an implementation detail of CPython.  The test about
+        # rendering zeroes failed while using PyPy when using "is".
+        # See issue #34: https://github.com/defunkt/pystache/issues/34
+        if not val and val != 0:
+            if tag_name != '.':
+                return ''
+            val = self.context.top()
 
         if callable(val):
             # According to the spec:
@@ -412,8 +416,25 @@ class Template(object):
             template = val()
             val = self.render_template(template, context)
 
-            u = self.to_unicode(val)
-            return u
+        if not isinstance(val, basestring):
+            val = str(val)
+
+        return val
+
+
+    def escape_tag_function(self, name):
+        get_literal = self.literal_tag_function(name)
+        def func(context):
+            s = self._get_string_value(context, name)
+            s = self.escape(s)
+            return s
+        return func
+
+    def literal_tag_function(self, name):
+        def func(context):
+            s = self._get_string_value(context, name)
+            s = self.to_unicode(s)
+            return s
 
         return func