From 8260eda522ce0e999642fdcf842370efe48d13a7 Mon Sep 17 00:00:00 2001
From: bigbag <bilbo.kem@gmail.com>
Date: Wed, 27 Mar 2019 15:38:09 +0200
Subject: [PATCH] Fix normalize_path_middleware behavior for patch without
 slash (3669) (#3670)

---
 CHANGES/3669.bugfix          |  1 +
 aiohttp/web_middlewares.py   |  2 +-
 tests/test_web_middleware.py | 23 ++++++++++++++++++++++-
 3 files changed, 24 insertions(+), 2 deletions(-)
 create mode 100644 CHANGES/3669.bugfix

diff --git a/CHANGES/3669.bugfix b/CHANGES/3669.bugfix
new file mode 100644
index 00000000000..5cdd3e0337c
--- /dev/null
+++ b/CHANGES/3669.bugfix
@@ -0,0 +1 @@
+Fix ``web_middlewares.normalize_path_middleware`` behavior for patch without slash.
\ No newline at end of file
diff --git a/aiohttp/web_middlewares.py b/aiohttp/web_middlewares.py
index a6a444b42d4..17064f6fb31 100644
--- a/aiohttp/web_middlewares.py
+++ b/aiohttp/web_middlewares.py
@@ -96,7 +96,7 @@ async def impl(request: Request, handler: _Handler) -> StreamResponse:
             if merge_slashes and append_slash:
                 paths_to_check.append(
                     re.sub('//+', '/', path + '/'))
-            if merge_slashes and remove_slash:
+            if merge_slashes and remove_slash and path.endswith('/'):
                 merged_slashes = re.sub('//+', '/', path)
                 paths_to_check.append(merged_slashes[:-1])
 
diff --git a/tests/test_web_middleware.py b/tests/test_web_middleware.py
index 2eba995d579..af199190abf 100644
--- a/tests/test_web_middleware.py
+++ b/tests/test_web_middleware.py
@@ -128,7 +128,9 @@ async def test_add_trailing_when_necessary(
         ('/resource2?p1=1&p2=2', 404),
         ('/resource2/?p1=1&p2=2', 200),
         ('/resource2/a/b%2Fc', 404),
-        ('/resource2/a/b%2Fc/', 200)
+        ('/resource2/a/b%2Fc/', 200),
+        ('/resource12', 404),
+        ('/resource12345', 404)
     ])
     async def test_remove_trailing_when_necessary(self, path,
                                                   status, cli) -> None:
@@ -276,6 +278,25 @@ async def test_cannot_remove_and_add_slash(self) -> None:
             web.normalize_path_middleware(append_slash=True, remove_slash=True)
 
 
+async def test_bug_3669(aiohttp_client):
+    async def paymethod(request):
+        return web.Response(text="OK")
+
+    app = web.Application()
+    app.router.add_route('GET', '/paymethod', paymethod)
+    app.middlewares.append(
+        web.normalize_path_middleware(append_slash=False, remove_slash=True)
+    )
+
+    client = await aiohttp_client(
+        app, server_kwargs={'skip_url_asserts': True}
+    )
+
+    resp = await client.get('/paymethods')
+    assert resp.status == 404
+    assert resp.url.path != '/paymethod'
+
+
 async def test_old_style_middleware(loop, aiohttp_client) -> None:
     async def handler(request):
         return web.Response(body=b'OK')