Comment 16 for bug 1657459

Reviewed: https://review.openstack.org/423366
Committed: https://git.openstack.org/cgit/openstack/glance/commit/?id=7a843f7e1fb1bab504fea0b2c59bf7c22121da71
Submitter: Jenkins
Branch: master

commit 7a843f7e1fb1bab504fea0b2c59bf7c22121da71
Author: Ian Cordasco <email address hidden>
Date: Fri Jan 20 16:38:10 2017 +0000

    Fix incompatibilities with WebOb 1.7

    WebOb 1.7 changed [0] how request bodies are determined to be
    readable. Prior to version 1.7, the following is how WebOb
    determined if a request body is readable:
      #1 Request method is one of POST, PUT or PATCH
      #2 ``content_length`` length is set
      #3 Special flag ``webob.is_body_readable`` is set

    The special flag ``webob.is_body_readable`` was used to signal
    WebOb to consider a request body readable despite the content length
    not being set. #1 above is how ``chunked`` Transfer Encoding was
    supported implicitly in WebOb < 1.7.

    Now with WebOb 1.7, a request body is considered readable only if
    ``content_length`` is set and it's non-zero [1]. So, we are only left
    with #2 and #3 now. This drops implicit support for ``chunked``
    Transfer Encoding Glance relied on. Hence, to emulate #1, Glance must
    set the the special flag upon checking the HTTP methods that may have
    bodies. This is precisely what this patch attemps to do.

    [0] https://github.com/Pylons/webob/pull/283
    [1] https://github.com/Pylons/webob/pull/283/files#diff-706d71e82f473a3b61d95c2c0d833b60R894

    Closes-bug: #1657459
    Closes-bug: #1657452
    Co-Authored-By: Hemanth Makkapati <email address hidden>
    Change-Id: I19f15165a3d664d5f3a361f29ad7000ba2465a85