libstc++ (?) problem on CURRENT?

>On Sat, Nov 6, 2010 at 10:57 AM, Barbara <barbara.xxx1975_at_libero.it> wrote:
>>
>> I had a problem running the IcedTea java plugin on CURRENT i386, while it
>> works on 8_STABLE.
>> But maybe it's not a problem related to the port.
>> Just to be clear, I'm not looking for a solution about the port here, I'm 
just
>> wondering why the same c++ code is working on 8_STABLE and it's segfaulting 
on
>> CURRENT, considering also that AFAIK the gcc version in both the base 
systems
>> is the same.
>>
>> In the part of the code causing the crash, a std::map is read with an 
iterator
>> in a for loop, and if a condition is met, an entry is erased.
>> The following is the bt I'm getting:
>> #0  0x29e36247 in kill () from /lib/libc.so.7
>> #1  0x29e361a6 in raise () from /lib/libc.so.7
>> #2  0x282424f6 in XRE_LockProfileDirectory () from
>>        /usr/local/lib/firefox3/libxul.so
>> #3  <signal handler called>
>> #4  0x29c8f1b2 in std::_Rb_tree_increment () from
>>        /usr/lib/libstdc++.so.6 #5  0x2ef92402 in
>>        IcedTeaPluginUtilities::invalidateInstance () from
>>        /usr/local/openjdk6/jre/lib/IcedTeaPlugin.so
>> ...
>>
>> I wrote a "patch" for the IcedTea plugin, replacing the for loop with a 
while
>> and increasing the iterator before erasing from the map, and it seems 
working.
>> Then I wrote a simple program that do something similar to IcedTea, so 
there
>> is no need to build the whole java/openjdk6 port to do some testing.
>> Running it on 8_STABLE it works, on CURRENT it crashes.
>> You can find more details in this discussion on the freebsd-java ml:
>> http://lists.freebsd.org/pipermail/freebsd-java/2010-November/008978.html
>>
>> You can find the patch and the sample code in the discussion above, anyway 
I'm
>> reporting them here too:
>> icedtea patch:
>> http://pastebin.com/b2KKFNSG
>> test case:
>> http://pastebin.com/Amk4UJ0g
>
>You appear to invalidate the iterator inside the loop and then
>increment it. Do the following:
>
>-- cut here --
>for (iter = cars.begin(); iter != cars.end(); ) {
> if ((*iter).second == modelName)
>  cars.erase(iter++);
> else
>  ++iter;
>}
>-- and here --
>
>In this example, you first increment the iterator and then erase its
>previous value.
>

So there is a bug in my source code! Well, I'm not surprised.

I'm trying to report the code in icedtea here, extracting it from the patch so 
I hope it's accurate enough:

    std::map<void*,NPP>::iterator iterator; 
    for (iterator = instance_map->begin(); iterator != instance_map->end(); 
iterator++)
    {
      if ((*iterator).second == instance)
        {
           instance_map->erase((*iterator).first);
        }
     }

So, do you think, like Ed Schouten said, that there is a bug in the source 
code but it's just exposed on CURRENT?
Is that code bad too?

Thanks
Barbara