We are currently solving the following issue within our repository. Here is the issue text:
--- BEGIN ISSUE ---
Redirect a slash-less URL to the slashed variant
We have urls like `/project/foobar/`, if someone enters `/project/foobar` we should redirect that to `/project/foobar/`.


--- END ISSUE ---

Below are some code segments, each from a relevant file. One or more of these files may contain bugs.
--- BEGIN FILES ---
Path: `warehouse/config.py`
Content:
```
1 # Licensed under the Apache License, Version 2.0 (the "License");
2 # you may not use this file except in compliance with the License.
3 # You may obtain a copy of the License at
4 #
5 # http://www.apache.org/licenses/LICENSE-2.0
6 #
7 # Unless required by applicable law or agreed to in writing, software
8 # distributed under the License is distributed on an "AS IS" BASIS,
9 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
10 # See the License for the specific language governing permissions and
11 # limitations under the License.
12 
13 import fs.opener
14 import transaction
15 
16 from pyramid.config import Configurator
17 from tzf.pyramid_yml import config_defaults
18 
19 from warehouse.utils.static import WarehouseCacheBuster
20 
21 
22 def content_security_policy_tween_factory(handler, registry):
23     policy = registry.settings.get("csp", {})
24     policy = "; ".join([" ".join([k] + v) for k, v in sorted(policy.items())])
25 
26     def content_security_policy_tween(request):
27         resp = handler(request)
28 
29         # We don't want to apply our Content Security Policy to the debug
30         # toolbar, that's not part of our application and it doesn't work with
31         # our restrictive CSP.
32         if not request.path.startswith("/_debug_toolbar/"):
33             resp.headers["Content-Security-Policy"] = \
34                 policy.format(request=request)
35 
36         return resp
37 
38     return content_security_policy_tween
39 
40 
41 def configure(settings=None):
42     if settings is None:
43         settings = {}
44 
45     config = Configurator(settings=settings)
46 
47     # Set our yml.location so that it contains all of our settings files
48     config_defaults(config, ["warehouse:etc"])
49 
50     # We want to load configuration from YAML files
51     config.include("tzf.pyramid_yml")
52 
53     # We'll want to use Jinja2 as our template system.
54     config.include("pyramid_jinja2")
55 
56     # We also want to use Jinja2 for .html templates as well, because we just
57     # assume that all templates will be using Jinja.
58     config.add_jinja2_renderer(".html")
59 
60     # We'll want to configure some filters for Jinja2 as well.
61     filters = config.get_settings().setdefault("jinja2.filters", {})
62     filters.setdefault("readme", "warehouse.filters:readme_renderer")
63     filters.setdefault("shorten_number", "warehouse.filters:shorten_number")
64 
65     # We also want to register some global functions for Jinja
66     jglobals = config.get_settings().setdefault("jinja2.globals", {})
67     jglobals.setdefault("gravatar", "warehouse.utils.gravatar:gravatar")
68 
69     # We'll store all of our templates in one location, warehouse/templates
70     # so we'll go ahead and add that to the Jinja2 search path.
71     config.add_jinja2_search_path("warehouse:templates", name=".html")
72 
73     # Configure our transaction handling so that each request gets it's own
74     # transaction handler and the lifetime of the transaction is tied to the
75     # lifetime of the request.
76     config.add_settings({
77         "tm.manager_hook": lambda request: transaction.TransactionManager(),
78     })
79     config.include("pyramid_tm")
80 
81     # Register support for services
82     config.include("pyramid_services")
83 
84     # Register support for internationalization and localization
85     config.include(".i18n")
86 
87     # Register the configuration for the PostgreSQL database.
88     config.include(".db")
89 
90     # Register our session support
91     config.include(".sessions")
92 
93     # Register our support for http and origin caching
94     config.include(".cache.http")
95     config.include(".cache.origin")
96 
97     # Register our CSRF support
98     config.include(".csrf")
99 
100     # Register our authentication support.
101     config.include(".accounts")
102 
103     # Allow the packaging app to register any services it has.
104     config.include(".packaging")
105 
106     # Register all our URL routes for Warehouse.
107     config.include(".routes")
108 
109     # Enable a Content Security Policy
110     config.add_settings({
111         "csp": {
112             "default-src": ["'none'"],
113             "frame-ancestors": ["'none'"],
114             "img-src": [
115                 "'self'",
116                 config.registry.settings["camo.url"],
117                 "https://secure.gravatar.com",
118             ],
119             "referrer": ["cross-origin"],
120             "reflected-xss": ["block"],
121             "script-src": ["'self'"],
122             "style-src": ["'self'"],
123         },
124     })
125     config.add_tween("warehouse.config.content_security_policy_tween_factory")
126 
127     # Configure the filesystems we use.
128     config.registry["filesystems"] = {}
129     for key, path in {
130             k[5:]: v
131             for k, v in config.registry.settings.items()
132             if k.startswith("dirs.")}.items():
133         config.registry["filesystems"][key] = \
134             fs.opener.fsopendir(path, create_dir=True)
135 
136     # Enable Warehouse to service our static files
137     config.add_static_view(
138         name="static",
139         path="warehouse:static",
140         cachebust=WarehouseCacheBuster(
141             "warehouse:static/manifest.json",
142             cache=not config.registry.settings["pyramid.reload_assets"],
143         ),
144     )
145 
146     # Scan everything for configuration
147     config.scan(ignore=["warehouse.migrations.env"])
148 
149     return config
150
```
--- END FILES ---

Please first localize the bug based on the issue statement, and then generate a patch according to the `git diff` format fenced by three backticks.

Here is an example:

```diff
diff --git a/examples/server_async.py b/examples/server_async.py
--- a/examples/server_async.py
+++ b/examples/server_async.py
@@ -313,4 +313,4 @@
 
 
 if __name__ == "__main__":
-    asyncio.run(run_async_server("."), debug=True)
+    asyncio.run(run_async_server(), debug=True)
diff --git a/examples/server_sync.py b/examples/server_sync.py
--- a/examples/server_sync.py
+++ b/examples/server_sync.py
@@ -313,5 +313,5 @@
 
 
 if __name__ == "__main__":
-    server = run_sync_server(".")
+    server = run_sync_server()
     server.shutdown()

```

diff --git a/warehouse/config.py b/warehouse/config.py
--- a/warehouse/config.py
+++ b/warehouse/config.py
@@ -124,6 +124,10 @@
     })
     config.add_tween("warehouse.config.content_security_policy_tween_factory")
 
+    # If a route matches with a slash appended to it, redirect to that route
+    # instead of returning a HTTPNotFound.
+    config.add_notfound_view(append_slash=True)
+
     # Configure the filesystems we use.
     config.registry["filesystems"] = {}
     for key, path in {

{"golden_diff": "diff --git a/warehouse/config.py b/warehouse/config.py\n--- a/warehouse/config.py\n+++ b/warehouse/config.py\n@@ -124,6 +124,10 @@\n     })\n     config.add_tween(\"warehouse.config.content_security_policy_tween_factory\")\n \n+    # If a route matches with a slash appended to it, redirect to that route\n+    # instead of returning a HTTPNotFound.\n+    config.add_notfound_view(append_slash=True)\n+\n     # Configure the filesystems we use.\n     config.registry[\"filesystems\"] = {}\n     for key, path in {\n", "issue": "Redirect a slash-less URL to the slashed variant\nWe have urls like `/project/foobar/`, if someone enters `/project/foobar` we should redirect that to `/project/foobar/`.\n\n", "before_files": [{"content": "# Licensed under the Apache License, Version 2.0 (the \"License\");\n# you may not use this file except in compliance with the License.\n# You may obtain a copy of the License at\n#\n# http://www.apache.org/licenses/LICENSE-2.0\n#\n# Unless required by applicable law or agreed to in writing, software\n# distributed under the License is distributed on an \"AS IS\" BASIS,\n# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\n# See the License for the specific language governing permissions and\n# limitations under the License.\n\nimport fs.opener\nimport transaction\n\nfrom pyramid.config import Configurator\nfrom tzf.pyramid_yml import config_defaults\n\nfrom warehouse.utils.static import WarehouseCacheBuster\n\n\ndef content_security_policy_tween_factory(handler, registry):\n    policy = registry.settings.get(\"csp\", {})\n    policy = \"; \".join([\" \".join([k] + v) for k, v in sorted(policy.items())])\n\n    def content_security_policy_tween(request):\n        resp = handler(request)\n\n        # We don't want to apply our Content Security Policy to the debug\n        # toolbar, that's not part of our application and it doesn't work with\n        # our restrictive CSP.\n        if not request.path.startswith(\"/_debug_toolbar/\"):\n            resp.headers[\"Content-Security-Policy\"] = \\\n                policy.format(request=request)\n\n        return resp\n\n    return content_security_policy_tween\n\n\ndef configure(settings=None):\n    if settings is None:\n        settings = {}\n\n    config = Configurator(settings=settings)\n\n    # Set our yml.location so that it contains all of our settings files\n    config_defaults(config, [\"warehouse:etc\"])\n\n    # We want to load configuration from YAML files\n    config.include(\"tzf.pyramid_yml\")\n\n    # We'll want to use Jinja2 as our template system.\n    config.include(\"pyramid_jinja2\")\n\n    # We also want to use Jinja2 for .html templates as well, because we just\n    # assume that all templates will be using Jinja.\n    config.add_jinja2_renderer(\".html\")\n\n    # We'll want to configure some filters for Jinja2 as well.\n    filters = config.get_settings().setdefault(\"jinja2.filters\", {})\n    filters.setdefault(\"readme\", \"warehouse.filters:readme_renderer\")\n    filters.setdefault(\"shorten_number\", \"warehouse.filters:shorten_number\")\n\n    # We also want to register some global functions for Jinja\n    jglobals = config.get_settings().setdefault(\"jinja2.globals\", {})\n    jglobals.setdefault(\"gravatar\", \"warehouse.utils.gravatar:gravatar\")\n\n    # We'll store all of our templates in one location, warehouse/templates\n    # so we'll go ahead and add that to the Jinja2 search path.\n    config.add_jinja2_search_path(\"warehouse:templates\", name=\".html\")\n\n    # Configure our transaction handling so that each request gets it's own\n    # transaction handler and the lifetime of the transaction is tied to the\n    # lifetime of the request.\n    config.add_settings({\n        \"tm.manager_hook\": lambda request: transaction.TransactionManager(),\n    })\n    config.include(\"pyramid_tm\")\n\n    # Register support for services\n    config.include(\"pyramid_services\")\n\n    # Register support for internationalization and localization\n    config.include(\".i18n\")\n\n    # Register the configuration for the PostgreSQL database.\n    config.include(\".db\")\n\n    # Register our session support\n    config.include(\".sessions\")\n\n    # Register our support for http and origin caching\n    config.include(\".cache.http\")\n    config.include(\".cache.origin\")\n\n    # Register our CSRF support\n    config.include(\".csrf\")\n\n    # Register our authentication support.\n    config.include(\".accounts\")\n\n    # Allow the packaging app to register any services it has.\n    config.include(\".packaging\")\n\n    # Register all our URL routes for Warehouse.\n    config.include(\".routes\")\n\n    # Enable a Content Security Policy\n    config.add_settings({\n        \"csp\": {\n            \"default-src\": [\"'none'\"],\n            \"frame-ancestors\": [\"'none'\"],\n            \"img-src\": [\n                \"'self'\",\n                config.registry.settings[\"camo.url\"],\n                \"https://secure.gravatar.com\",\n            ],\n            \"referrer\": [\"cross-origin\"],\n            \"reflected-xss\": [\"block\"],\n            \"script-src\": [\"'self'\"],\n            \"style-src\": [\"'self'\"],\n        },\n    })\n    config.add_tween(\"warehouse.config.content_security_policy_tween_factory\")\n\n    # Configure the filesystems we use.\n    config.registry[\"filesystems\"] = {}\n    for key, path in {\n            k[5:]: v\n            for k, v in config.registry.settings.items()\n            if k.startswith(\"dirs.\")}.items():\n        config.registry[\"filesystems\"][key] = \\\n            fs.opener.fsopendir(path, create_dir=True)\n\n    # Enable Warehouse to service our static files\n    config.add_static_view(\n        name=\"static\",\n        path=\"warehouse:static\",\n        cachebust=WarehouseCacheBuster(\n            \"warehouse:static/manifest.json\",\n            cache=not config.registry.settings[\"pyramid.reload_assets\"],\n        ),\n    )\n\n    # Scan everything for configuration\n    config.scan(ignore=[\"warehouse.migrations.env\"])\n\n    return config\n", "path": "warehouse/config.py"}], "after_files": [{"content": "# Licensed under the Apache License, Version 2.0 (the \"License\");\n# you may not use this file except in compliance with the License.\n# You may obtain a copy of the License at\n#\n# http://www.apache.org/licenses/LICENSE-2.0\n#\n# Unless required by applicable law or agreed to in writing, software\n# distributed under the License is distributed on an \"AS IS\" BASIS,\n# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\n# See the License for the specific language governing permissions and\n# limitations under the License.\n\nimport fs.opener\nimport transaction\n\nfrom pyramid.config import Configurator\nfrom tzf.pyramid_yml import config_defaults\n\nfrom warehouse.utils.static import WarehouseCacheBuster\n\n\ndef content_security_policy_tween_factory(handler, registry):\n    policy = registry.settings.get(\"csp\", {})\n    policy = \"; \".join([\" \".join([k] + v) for k, v in sorted(policy.items())])\n\n    def content_security_policy_tween(request):\n        resp = handler(request)\n\n        # We don't want to apply our Content Security Policy to the debug\n        # toolbar, that's not part of our application and it doesn't work with\n        # our restrictive CSP.\n        if not request.path.startswith(\"/_debug_toolbar/\"):\n            resp.headers[\"Content-Security-Policy\"] = \\\n                policy.format(request=request)\n\n        return resp\n\n    return content_security_policy_tween\n\n\ndef configure(settings=None):\n    if settings is None:\n        settings = {}\n\n    config = Configurator(settings=settings)\n\n    # Set our yml.location so that it contains all of our settings files\n    config_defaults(config, [\"warehouse:etc\"])\n\n    # We want to load configuration from YAML files\n    config.include(\"tzf.pyramid_yml\")\n\n    # We'll want to use Jinja2 as our template system.\n    config.include(\"pyramid_jinja2\")\n\n    # We also want to use Jinja2 for .html templates as well, because we just\n    # assume that all templates will be using Jinja.\n    config.add_jinja2_renderer(\".html\")\n\n    # We'll want to configure some filters for Jinja2 as well.\n    filters = config.get_settings().setdefault(\"jinja2.filters\", {})\n    filters.setdefault(\"readme\", \"warehouse.filters:readme_renderer\")\n    filters.setdefault(\"shorten_number\", \"warehouse.filters:shorten_number\")\n\n    # We also want to register some global functions for Jinja\n    jglobals = config.get_settings().setdefault(\"jinja2.globals\", {})\n    jglobals.setdefault(\"gravatar\", \"warehouse.utils.gravatar:gravatar\")\n\n    # We'll store all of our templates in one location, warehouse/templates\n    # so we'll go ahead and add that to the Jinja2 search path.\n    config.add_jinja2_search_path(\"warehouse:templates\", name=\".html\")\n\n    # Configure our transaction handling so that each request gets it's own\n    # transaction handler and the lifetime of the transaction is tied to the\n    # lifetime of the request.\n    config.add_settings({\n        \"tm.manager_hook\": lambda request: transaction.TransactionManager(),\n    })\n    config.include(\"pyramid_tm\")\n\n    # Register support for services\n    config.include(\"pyramid_services\")\n\n    # Register support for internationalization and localization\n    config.include(\".i18n\")\n\n    # Register the configuration for the PostgreSQL database.\n    config.include(\".db\")\n\n    # Register our session support\n    config.include(\".sessions\")\n\n    # Register our support for http and origin caching\n    config.include(\".cache.http\")\n    config.include(\".cache.origin\")\n\n    # Register our CSRF support\n    config.include(\".csrf\")\n\n    # Register our authentication support.\n    config.include(\".accounts\")\n\n    # Allow the packaging app to register any services it has.\n    config.include(\".packaging\")\n\n    # Register all our URL routes for Warehouse.\n    config.include(\".routes\")\n\n    # Enable a Content Security Policy\n    config.add_settings({\n        \"csp\": {\n            \"default-src\": [\"'none'\"],\n            \"frame-ancestors\": [\"'none'\"],\n            \"img-src\": [\n                \"'self'\",\n                config.registry.settings[\"camo.url\"],\n                \"https://secure.gravatar.com\",\n            ],\n            \"referrer\": [\"cross-origin\"],\n            \"reflected-xss\": [\"block\"],\n            \"script-src\": [\"'self'\"],\n            \"style-src\": [\"'self'\"],\n        },\n    })\n    config.add_tween(\"warehouse.config.content_security_policy_tween_factory\")\n\n    # If a route matches with a slash appended to it, redirect to that route\n    # instead of returning a HTTPNotFound.\n    config.add_notfound_view(append_slash=True)\n\n    # Configure the filesystems we use.\n    config.registry[\"filesystems\"] = {}\n    for key, path in {\n            k[5:]: v\n            for k, v in config.registry.settings.items()\n            if k.startswith(\"dirs.\")}.items():\n        config.registry[\"filesystems\"][key] = \\\n            fs.opener.fsopendir(path, create_dir=True)\n\n    # Enable Warehouse to service our static files\n    config.add_static_view(\n        name=\"static\",\n        path=\"warehouse:static\",\n        cachebust=WarehouseCacheBuster(\n            \"warehouse:static/manifest.json\",\n            cache=not config.registry.settings[\"pyramid.reload_assets\"],\n        ),\n    )\n\n    # Scan everything for configuration\n    config.scan(ignore=[\"warehouse.migrations.env\"])\n\n    return config\n", "path": "warehouse/config.py"}]}