[Bug libstdc++/64140] match_results.prefix() returns an incorrect result if regex_iterator holds a zero-length match

[timshen at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64140

--- Comment #2 from Tim Shen <timshen at gcc dot gnu.org> ---
Author: timshen
Date: Sat Dec  6 11:32:21 2014
New Revision: 218445

URL: https://gcc.gnu.org/viewcvs?rev=218445&root=gcc&view=rev
Log:
    PR libstdc++/64140
    Backport form mainline
    2014-12-04  Tim Shen  <tims...@google.com>

    * include/bits/regex.tcc (regex_iterator<>::operator++): Update
    prefix.matched after modifying prefix.first.
    * testsuite/28_regex/iterators/regex_iterator/char/64140.cc: New
    testcase.

Added:
   
branches/gcc-4_9-branch/libstdc++-v3/testsuite/28_regex/iterators/regex_iterator/char/64140.cc
Modified:
    branches/gcc-4_9-branch/libstdc++-v3/ChangeLog
    branches/gcc-4_9-branch/libstdc++-v3/include/bits/regex.tcc