[issue21705] cgi.py: Multipart with more than one file is misparsed

[Matthias Urlichs]

New submission from Matthias Urlichs:

This code in cgi.py makes no sense whatsoever:

842                 if line.endswith(b"--") and last_line_lfend:
843                     strippedline = line.strip()
844                     if strippedline == next_boundary:
845                         break
846                     if strippedline == last_boundary:
847                         self.done = 1
848                         break

(Pdb) p next_boundary
b'--testdata'
(Pdb) p last_boundary
b'--testdata--'
(Pdb) 

The net effect of this is that parsing a multipart with more than one file in it is impossible, as the first file's reader will gobble up the remainder of the input.

Patch attached.

I guess it's a safe bet that no sane person even uses cgi.py any more, otherwise this would have been discovered a bit sooner.

----------
components: Library (Lib)
files: cgi.patch2
messages: 220164
nosy: smurfix
priority: normal
severity: normal
status: open
title: cgi.py: Multipart with more than one file is misparsed
type: behavior
versions: Python 3.3, Python 3.4, Python 3.5
Added file: http://bugs.python.org/file35552/cgi.patch2

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<http://bugs.python.org/issue21705>
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