[1.8.x] Fixed #13525 -- Added tests and docs for nested parameters in URL patterns.

When reversing, only outer parameters are used if captured parameters are
nested. Added tests to check the edge cases and documentation for the
behavior with an example to avoid it.

Backport of 23a5d64f40b0f4a3fbfef7427ca793cb1df1034e from master

2 files changed, 23 insertions, 0 deletions

diff --git a/tests/urlpatterns_reverse/tests.py b/tests/urlpatterns_reverse/tests.py
index 7c8c17a928..8f8496a515 100644
--- a/tests/urlpatterns_reverse/tests.py
+++ b/tests/urlpatterns_reverse/tests.py
@@ -94,6 +94,12 @@ test_data = (
     ('people_backref', '/people/nate-nate/', [], {'name': 'nate'}),
     ('optional', '/optional/fred/', [], {'name': 'fred'}),
     ('optional', '/optional/fred/', ['fred'], {}),
+    ('named_optional', '/optional/1/', [1], {}),
+    ('named_optional', '/optional/1/', [], {'arg1': 1}),
+    ('named_optional', '/optional/1/2/', [1, 2], {}),
+    ('named_optional', '/optional/1/2/', [], {'arg1': 1, 'arg2': 2}),
+    ('named_optional_terminated', '/optional/1/2/', [1, 2], {}),
+    ('named_optional_terminated', '/optional/1/2/', [], {'arg1': 1, 'arg2': 2}),
     ('hardcoded', '/hardcoded/', [], {}),
     ('hardcoded2', '/hardcoded/doc.pdf', [], {}),
     ('people3', '/people/il/adrian/', [], {'state': 'il', 'name': 'adrian'}),
@@ -142,6 +148,17 @@ test_data = (
     ('part2', '/prefix/xx/part2/one/', [], {'value': 'one', 'prefix': 'xx'}),
     ('part2', '/prefix/xx/part2/', [], {'prefix': 'xx'}),
 
+    # Tests for nested groups. Nested capturing groups will only work if you
+    # *only* supply the correct outer group.
+    ('nested-noncapture', '/nested/noncapture/opt', [], {'p': 'opt'}),
+    ('nested-capture', '/nested/capture/opt/', ['opt/'], {}),
+    ('nested-capture', NoReverseMatch, [], {'p': 'opt'}),
+    ('nested-mixedcapture', '/nested/capture/mixed/opt', ['opt'], {}),
+    ('nested-mixedcapture', NoReverseMatch, [], {'p': 'opt'}),
+    ('nested-namedcapture', '/nested/capture/named/opt/', [], {'outer': 'opt/'}),
+    ('nested-namedcapture', NoReverseMatch, [], {'outer': 'opt/', 'inner': 'opt'}),
+    ('nested-namedcapture', NoReverseMatch, [], {'inner': 'opt'}),
+
     # Regression for #9038
     # These views are resolved by method name. Each method is deployed twice -
     # once with an explicit argument, and once using the default value on
diff --git a/tests/urlpatterns_reverse/urls.py b/tests/urlpatterns_reverse/urls.py
index 9b5a5f29fa..d6b692d220 100644
--- a/tests/urlpatterns_reverse/urls.py
+++ b/tests/urlpatterns_reverse/urls.py
@@ -32,6 +32,12 @@ with warnings.catch_warnings():
         url(r'^people/(?:name/(\w+)/)?', empty_view, name="people2a"),
         url(r'^people/(?P<name>\w+)-(?P=name)/$', empty_view, name="people_backref"),
         url(r'^optional/(?P<name>.*)/(?:.+/)?', empty_view, name="optional"),
+        url(r'^optional/(?P<arg1>\d+)/(?:(?P<arg2>\d+)/)?', absolute_kwargs_view, name="named_optional"),
+        url(r'^optional/(?P<arg1>\d+)/(?:(?P<arg2>\d+)/)?$', absolute_kwargs_view, name="named_optional_terminated"),
+        url(r'^nested/noncapture/(?:(?P<p>\w+))$', empty_view, name='nested-noncapture'),
+        url(r'^nested/capture/((\w+)/)?$', empty_view, name='nested-capture'),
+        url(r'^nested/capture/mixed/((?P<p>\w+))$', empty_view, name='nested-mixedcapture'),
+        url(r'^nested/capture/named/(?P<outer>(?P<inner>\w+)/)?$', empty_view, name='nested-namedcapture'),
         url(r'^hardcoded/$', empty_view, name="hardcoded"),
         url(r'^hardcoded/doc\.pdf$', empty_view, name="hardcoded2"),
         url(r'^people/(?P<state>\w\w)/(?P<name>\w+)/$', empty_view, name="people3"),