[Bug libstdc++/53984] New: iostream operation throwing exception when exceptions not enabled

[Bug libstdc++/53984] New: iostream operation throwing exception when exceptions not enabled

[gccbz.10.petechap at spamgourmet dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53984

             Bug #: 53984
           Summary: iostream operation throwing exception when exceptions
                    not enabled
    Classification: Unclassified
           Product: gcc
           Version: 4.6.3
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: gccbz.10.petechap@spamgourmet.com


I'm getting an exception thrown in a situation where I believe a failbit should
be set instead.
Is my expectation wrong?

-------------------
#include <fstream>
#include <sstream>

int main()
{
    std::ifstream in(".");
    std::ostringstream out;
    if (in)
      in >> out.rdbuf();
}
-------------------


terminate called after throwing an instance of 'std::ios_base::failure'
  what():  basic_filebuf::underflow error reading the file
Aborted (core dumped)

[Bug libstdc++/53984] iostream operation throwing exception when exceptions not enabled

[gccbz.10.petechap at spamgourmet dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53984

--- Comment #1 from Pete Chapman <gccbz.10.petechap at spamgourmet dot com> 2012-07-16 17:00:10 UTC ---
Even simpler:

-------------------
#include <fstream>
int main()
{
        std::ifstream in(".");
        int x;
        if (in)
          in >> x;
}
-------------------

[Bug libstdc++/53984] iostream operation throwing exception when exceptions not enabled

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53984

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2012-07-16
     Ever Confirmed|0                           |1

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> 2012-07-16 17:26:39 UTC ---
Confirmed, I'm not sure filebuf::underflow should throw on invalid byte
sequences either.

[Bug libstdc++/53984] iostream operation throwing exception when exceptions not enabled

[tom at kera dot name]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53984

Tomalak Geret'kal <tom at kera dot name> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |tom at kera dot name

--- Comment #3 from Tomalak Geret'kal <tom at kera dot name> ---
Another testcase was proposed under the following Stack Overflow question:

  http://stackoverflow.com/q/20371956/560648

The answer to that question was a link to this bug.

[Bug libstdc++/53984] iostream operation throwing exception when exceptions not enabled

[igorlord at alum dot mit.edu]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53984

--- Comment #4 from Igor <igorlord at alum dot mit.edu> ---
This is a really evil bug.  I wonder why the Importance is not higher.

This may crash programs that try to read many /proc files on Linux.


~$ g++ -x c++ -o test - <<EOF
#include <fstream>
#include <unistd.h>
int main(int argc, char *argv[])
{
    std::ifstream in(argv[1]);
    sleep(4);
    std::string s;
    if (in)
      in >> s;
    return 0;
}
EOF

~$ sleep 2 & ./test "/proc/${!}/stat"

terminate called after throwing an instance of 'std::ios_base::failure'
  what():  basic_filebuf::underflow error reading the file
Aborted (core dumped)