Fixed django#16774 -- Allow view to raise DoesNotResolve to make URL …

…Resolver to keep searching for a URL.

django/core/handlers/base.py

@@ -100,7 +100,12 @@ def get_response(self, request):
                         urlconf = request.urlconf
                         urlresolvers.set_urlconf(urlconf)
                         resolver = urlresolvers.RegexURLResolver(r'^/', urlconf)
+                # Use generators and try to resolve matching URL patterns one by
+                # one
+                url_patterns = (pattern for pattern in resolver.url_patterns)
+                resolver = urlresolvers.RegexURLResolver(r'^/', url_patterns)
 
+                while response is None:
                     callback, callback_args, callback_kwargs = resolver.resolve(
                             request.path_info)
 
@@ -110,19 +115,24 @@ def get_response(self, request):
                         if response:
                             break
 
-                if response is None:
-                    try:
-                        response = callback(request, *callback_args, **callback_kwargs)
-                    except Exception as e:
-                        # If the view raised an exception, run it through exception
-                        # middleware, and if the exception middleware returns a
-                        # response, use that. Otherwise, reraise the exception.
-                        for middleware_method in self._exception_middleware:
-                            response = middleware_method(request, e)
-                            if response:
-                                break
-                        if response is None:
-                            raise
+                    if response is None:
+                        try:
+                            response = callback(request, *callback_args, **callback_kwargs)
+                        except urlresolvers.DoesNotResolve, e:
+                            # Continue resolve URLs if the view raises 
+                            # urlresolvers.DoesNotResolve exception to indicate
+                            # the url pattern does not match.
+                            continue
+                        except Exception as e:
+                            # If the view raised an exception, run it through exception
+                            # middleware, and if the exception middleware returns a
+                            # response, use that. Otherwise, reraise the exception.
+                            for middleware_method in self._exception_middleware:
+                                response = middleware_method(request, e)
+                                if response:
+                                    break
+                            if response is None:
+                                raise
 
                 # Complain if the view returned None (a common error).
                 if response is None:

django/core/urlresolvers.py

@@ -73,6 +73,9 @@ def __repr__(self):
 class Resolver404(Http404):
     pass
 
+class DoesNotResolve(Http404):
+    pass
+
 class NoReverseMatch(Exception):
     # Don't make this raise an error when used in a template.
     silent_variable_failure = True

tests/regressiontests/views/generic_urls.py

@@ -54,4 +54,8 @@
     (r'^shortcuts/render/status/$', 'render_view_with_status'),
     (r'^shortcuts/render/current_app/$', 'render_view_with_current_app'),
     (r'^shortcuts/render/current_app_conflict/$', 'render_view_with_current_app_conflict'),
+    url(r'^overlapping_view/(?P<title>[a-z]+)/$', 'overlapping_view1', name='overlapping_view1'),
+    url(r'^overlapping_view/(?P<author>[a-z]+)/$', 'overlapping_view2', name='overlapping_view2'),
+    url(r'^overlapping_view/(?P<keywords>[a-z]+)/$', 'overlapping_view3', name='overlapping_view3'),
+    url(r'^no_overlapping_view/(?P<keywords>[a-z]+)/$', 'no_overlapping_view', name='no_overlapping_view'),
 )

tests/regressiontests/views/tests/specials.py

@@ -37,3 +37,17 @@ def test_permanent_nonascii_redirect(self):
         response = self.client.get('/permanent_nonascii_redirect/')
         self.assertRedirects(response, self.redirect_target, status_code=301)
 
+    def test_overlapping_urls_reverse(self):
+        from django.core import urlresolvers
+        url = urlresolvers.reverse('overlapping_view1', kwargs={'title':'sometitle'})
+        self.assertEqual(url, '/overlapping_view/sometitle/')
+        url = urlresolvers.reverse('overlapping_view2', kwargs={'author':'someauthor'})
+        self.assertEqual(url, '/overlapping_view/someauthor/')
+
+    def test_overlapping_urls_resolve(self):
+        response = self.client.get('/overlapping_view/sometitle/')
+        self.assertContains(response, 'overlapping_view2')
+
+    def test_overlapping_urls_not_resolve(self):
+        response = self.client.get('/no_overlapping_view/sometitle/')
+        self.assertEqual(response.status_code, 404)

tests/regressiontests/views/views.py

@@ -3,7 +3,7 @@
 import sys
 
 from django.core.exceptions import PermissionDenied
-from django.core.urlresolvers import get_resolver
+from django.core.urlresolvers import get_resolver, DoesNotResolve
 from django.http import HttpResponse, HttpResponseRedirect
 from django.shortcuts import render_to_response, render
 from django.template import Context, RequestContext, TemplateDoesNotExist
@@ -226,5 +226,18 @@ def method(self, request):
             send_log(request, exc_info)
             return technical_500_response(request, *exc_info)
 
+def overlapping_view1(request, title=None):
+    raise DoesNotResolve
+
+def overlapping_view2(request, author=None):
+    return HttpResponse("overlapping_view2")
+
+def overlapping_view3(request, keywords=None):
+    return HttpResponse("overlapping_view3")
+
+def no_overlapping_view(request, keywords=None):
+    raise DoesNotResolve
+
+
 def sensitive_method_view(request):
     return Klass().method(request)