Merge pull request #249 from Pylons/iobase

support iobase subclasses

4 files changed, 52 insertions, 1 deletions

diff --git a/CHANGES.txt b/CHANGES.txt
index 2897939..cabd3b5 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -54,6 +54,10 @@ Bugfixes
   bounds. These buffers now properly rotate and release their data.
   See https://github.com/Pylons/waitress/pull/242
 
+- Fix a bug in which non-seekable subclasses of ``io.IOBase`` would trigger
+  an exception when passed to the ``wsgi.file_wrapper`` callback.
+  See https://github.com/Pylons/waitress/pull/249
+
 1.2.1 (2019-01-25)
 ------------------
 
diff --git a/waitress/buffers.py b/waitress/buffers.py
index cacc094..aa11b70 100644
--- a/waitress/buffers.py
+++ b/waitress/buffers.py
@@ -129,6 +129,11 @@ class BytesIOBasedBuffer(FileBasedBuffer):
     def newfile(self):
         return BytesIO()
 
+def _is_seekable(fp):
+    if hasattr(fp, 'seekable'):
+        return fp.seekable()
+    return hasattr(fp, 'seek') and hasattr(fp, 'tell')
+
 class ReadOnlyFileBasedBuffer(FileBasedBuffer):
     # used as wsgi.file_wrapper
 
@@ -137,7 +142,7 @@ class ReadOnlyFileBasedBuffer(FileBasedBuffer):
         self.block_size = block_size # for __iter__
 
     def prepare(self, size=None):
-        if hasattr(self.file, 'seek') and hasattr(self.file, 'tell'):
+        if _is_seekable(self.file):
             start_pos = self.file.tell()
             self.file.seek(0, 2)
             end_pos = self.file.tell()
diff --git a/waitress/tests/fixtureapps/filewrapper.py b/waitress/tests/fixtureapps/filewrapper.py
index be35b02..d4e9a51 100644
--- a/waitress/tests/fixtureapps/filewrapper.py
+++ b/waitress/tests/fixtureapps/filewrapper.py
@@ -1,3 +1,4 @@
+import io
 import os
 
 here = os.path.dirname(os.path.abspath(__file__))
@@ -13,6 +14,23 @@ class KindaFilelike(object): # pragma: no cover
         self.bytes = self.bytes[n:]
         return bytes
 
+class UnseekableIOBase(io.RawIOBase): # pragma: no cover
+
+    def __init__(self, bytes):
+        self.buf = io.BytesIO(bytes)
+
+    def writable(self):
+        return False
+
+    def readable(self):
+        return True
+
+    def seekable(self):
+        return False
+
+    def read(self, n):
+        return self.buf.read(n)
+
 def app(environ, start_response): # pragma: no cover
     path_info = environ['PATH_INFO']
     if path_info.startswith('/filelike'):
@@ -48,6 +66,12 @@ def app(environ, start_response): # pragma: no cover
                 ('Content-Length', str(len(data))),
                 ('Content-Type', 'image/jpeg'),
             ]
+        elif path_info == '/notfilelike_iobase':
+            headers = [
+                ('Content-Length', str(len(data))),
+                ('Content-Type', 'image/jpeg'),
+            ]
+            f = UnseekableIOBase(data)
         elif path_info == '/notfilelike_nocl':
             headers = [('Content-Type', 'image/jpeg')]
         elif path_info == '/notfilelike_shortcl':
diff --git a/waitress/tests/test_functional.py b/waitress/tests/test_functional.py
index 0571ce6..25414ef 100644
--- a/waitress/tests/test_functional.py
+++ b/waitress/tests/test_functional.py
@@ -1223,6 +1223,24 @@ class FileWrapperTests(object):
             self.assertTrue(b'\377\330\377' in response_body)
             # connection has not been closed
 
+    def test_notfilelike_iobase_http11(self):
+        to_send = "GET /notfilelike_iobase HTTP/1.1\n\n"
+        to_send = tobytes(to_send)
+
+        self.connect()
+
+        for t in range(0, 2):
+            self.sock.send(to_send)
+            fp = self.sock.makefile('rb', 0)
+            line, headers, response_body = read_http(fp)
+            self.assertline(line, '200', 'OK', 'HTTP/1.1')
+            cl = int(headers['content-length'])
+            self.assertEqual(cl, len(response_body))
+            ct = headers['content-type']
+            self.assertEqual(ct, 'image/jpeg')
+            self.assertTrue(b'\377\330\377' in response_body)
+            # connection has not been closed
+
     def test_notfilelike_nocl_http11(self):
         to_send = "GET /notfilelike_nocl HTTP/1.1\n\n"
         to_send = tobytes(to_send)