prompt: 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()
  
  ```
  
golden_diff: 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 {
  
verification_info: {"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"}]}