std::string::assign

[Richard Kojedzinszky]

Dear All,

I've a strange bug, I've attached a small source which shows my issue.
So, I am trying to assign a string containing an embedded \0 in it. You 
will find that in test() I use std::string::assign to do this, but in two 
cases the results are different.

Please see the output of the attached source, and let me know if I am 
missing something, or it is a bug in g++/stdc++.

Of course, the third form in test() works as expected, but in my 
assumption all should.

With this g++ it behaves bad:
$ g++ -v
Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.7/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Debian 4.7.1-2' 
--with-bugurl=file:///usr/share/doc/gcc-4.7/README.Bugs 
--enable-languages=c,c++,go,fortran,objc,obj-c++ --prefix=/usr 
--program-suffix=-4.7 --enable-shared --enable-linker-build-id 
--with-system-zlib --libexecdir=/usr/lib --without-included-gettext 
--enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.7 
--libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu 
--enable-libstdcxx-debug --enable-libstdcxx-time=yes 
--enable-gnu-unique-object --enable-plugin --enable-objc-gc 
--with-arch-32=i586 --with-tune=generic --enable-checking=release 
--build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 4.7.1 (Debian 4.7.1-2)

But with freebsd's g++:
$ g++ -v
Using built-in specs.
Target: amd64-undermydesk-freebsd
Configured with: FreeBSD/amd64 system compiler
Thread model: posix
gcc version 4.2.1 20070831 patched [FreeBSD]

It works fine.


Thanks in advance,

Kojedzinszky Richard
Euronet Magyarorszag Informatikai Zrt.#include <iostream>
#include <string>
#include <cstring>

void test(const char *p)
{
	std::string v;

	v.assign(p, ::strlen(p)+1);

	std::cerr << "v=" << static_cast<const void*>(v.c_str()) << " size=" << v.size() << std::endl;

	v.assign(p, 1);

	std::cerr << "v=" << static_cast<const void*>(v.c_str()) << " size=" << v.size() << std::endl;

	v.assign(p);
	v.append(1, '\0');

	std::cerr << "a=" << static_cast<const void*>(v.c_str()) << " size=" << v.size() << std::endl;
}

int main()
{
	std::string x = "";

	test("");

	test(x.c_str());

}