bundling required python dependencies, to make it easier on Tails users

lib/flask/debughelpers.py

@@ -0,0 +1,87 @@
+# -*- coding: utf-8 -*-
+"""
+    flask.debughelpers
+    ~~~~~~~~~~~~~~~~~~
+
+    Various helpers to make the development experience better.
+
+    :copyright: (c) 2011 by Armin Ronacher.
+    :license: BSD, see LICENSE for more details.
+"""
+from ._compat import implements_to_string
+
+
+class UnexpectedUnicodeError(AssertionError, UnicodeError):
+    """Raised in places where we want some better error reporting for
+    unexpected unicode or binary data.
+    """
+
+
+@implements_to_string
+class DebugFilesKeyError(KeyError, AssertionError):
+    """Raised from request.files during debugging.  The idea is that it can
+    provide a better error message than just a generic KeyError/BadRequest.
+    """
+
+    def __init__(self, request, key):
+        form_matches = request.form.getlist(key)
+        buf = ['You tried to access the file "%s" in the request.files '
+               'dictionary but it does not exist.  The mimetype for the request '
+               'is "%s" instead of "multipart/form-data" which means that no '
+               'file contents were transmitted.  To fix this error you should '
+               'provide enctype="multipart/form-data" in your form.' %
+               (key, request.mimetype)]
+        if form_matches:
+            buf.append('\n\nThe browser instead transmitted some file names. '
+                       'This was submitted: %s' % ', '.join('"%s"' % x
+                            for x in form_matches))
+        self.msg = ''.join(buf)
+
+    def __str__(self):
+        return self.msg
+
+
+class FormDataRoutingRedirect(AssertionError):
+    """This exception is raised by Flask in debug mode if it detects a
+    redirect caused by the routing system when the request method is not
+    GET, HEAD or OPTIONS.  Reasoning: form data will be dropped.
+    """
+
+    def __init__(self, request):
+        exc = request.routing_exception
+        buf = ['A request was sent to this URL (%s) but a redirect was '
+               'issued automatically by the routing system to "%s".'
+               % (request.url, exc.new_url)]
+
+        # In case just a slash was appended we can be extra helpful
+        if request.base_url + '/' == exc.new_url.split('?')[0]:
+            buf.append('  The URL was defined with a trailing slash so '
+                       'Flask will automatically redirect to the URL '
+                       'with the trailing slash if it was accessed '
+                       'without one.')
+
+        buf.append('  Make sure to directly send your %s-request to this URL '
+                   'since we can\'t make browsers or HTTP clients redirect '
+                   'with form data reliably or without user interaction.' %
+                   request.method)
+        buf.append('\n\nNote: this exception is only raised in debug mode')
+        AssertionError.__init__(self, ''.join(buf).encode('utf-8'))
+
+
+def attach_enctype_error_multidict(request):
+    """Since Flask 0.8 we're monkeypatching the files object in case a
+    request is detected that does not use multipart form data but the files
+    object is accessed.
+    """
+    oldcls = request.files.__class__
+    class newcls(oldcls):
+        def __getitem__(self, key):
+            try:
+                return oldcls.__getitem__(self, key)
+            except KeyError as e:
+                if key not in request.form:
+                    raise
+                raise DebugFilesKeyError(request, key)
+    newcls.__name__ = oldcls.__name__
+    newcls.__module__ = oldcls.__module__
+    request.files.__class__ = newcls