[MODPYTHON-179] req.readlines(sizehint) does not work correctly

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 3.2.8
• Fix Version/s: 3.3.1
• Component/s: core
• Environment: All
• Assignee: James Paul Gallacher
• Reporter: James Paul Gallacher
• Created: 08/Jul/06 08:41
• Updated: 01/May/07 10:36
• Resolved: 09/Jul/06 20:03

Description

A bug in req_readlines(sizehint) in requestobject.c causes output to be returned prematurely for any value of the optional sizehint argument.

The faulty bit of code is:

line = req_readline(self, rlargs);
while (line && (PyString_Size(line)>0))

{ PyList_Append(result, line); size += PyString_Size(line); if ((sizehint != -1) && (size >= size)) break; line = req_readline(self, args); }

Since (size >= size) will always be true, reading the input stream will end prematurely for any value of sizehint != -1.

This code will fix the problem.

— requestobject.c (revision 417294)
+++ requestobject.c (working copy)
@@ -1154,7 +1154,7 @@
while (line && (PyString_Size(line)>0))

{ PyList_Append(result, line); size += PyString_Size(line); - if ((sizehint != -1) && (size >= size)) + if ((sizehint != -1) && (size >= sizehint)) break; line = req_readline(self, args); }

Once that is fixed the documentation needs to be revised, as it does not accurately reflect the behaviour of the code.

Currently the docs are:
"""Reads all or up to sizehint bytes of lines using readline and returns a list of the lines read."""

whereas the code can read beyond sizehint. The total read could actually be sizehint + len(line) where line is the last line read.