DR 243. get and getline when sentry reports failure [WP]
* include/bits/istream.tcc (istream<>::get, istream<>::getline):
Store a null character only if the array has a non-zero size.
* src/istream.cc (istream<char>::getline, istream<wchar_t>::getline):
Likewise.
* testsuite/27_io/basic_istream/get/char/3.cc: New.
* testsuite/27_io/basic_istream/getline/char/6.cc: New.
* testsuite/27_io/basic_istream/getline/wchar_t/6.cc: New.
* docs/html/ext/howto.html: Add an entry for DR 243.