Added break_long_headers on templatetags and base template

rest_framework/templates/rest_framework/base.html

@@ -115,7 +115,7 @@
             </div>
             <div class="response-info">
                 <pre class="prettyprint"><div class="meta nocode"><b>HTTP {{ response.status_code }} {{ response.status_text }}</b>{% autoescape off %}
-{% for key, val in response.items %}<b>{{ key }}:</b> <span class="lit">{{ val|urlize_quoted_links }}</span>
+{% for key, val in response.items %}<b>{{ key }}:</b> <span class="lit">{{ val|break_long_headers|urlize_quoted_links }}</span>
 {% endfor %}
 </div>{{ content|urlize_quoted_links }}</pre>{% endautoescape %}
             </div>

rest_framework/templatetags/rest_framework.py

@@ -260,3 +260,14 @@ def urlize_quoted_links(text, trim_url_limit=None, nofollow=True, autoescape=Tru
         elif autoescape:
             words[i] = escape(word)
     return ''.join(words)
+
+
+@register.filter
+def break_long_headers(header):
+    """
+    Breaks headers longer than 160 characters (~page length)
+    when possible (are comma separated)
+    """
+    if len(header) > 160:
+        header = mark_safe('<br> ' + ', <br>'.join(header.split(',')))
+    return header