Description of problem:
we are developing ABRT component for Fedora and need to create archives.
this simple code

int create_tar(const char * archive_name, const char * directory)
{
    TAR *tar; 

    tar_open(&tar, (char *)archive_name, NULL, O_WRONLY | O_CREAT, 0644, TAR_GNU);
    tar_append_tree(tar, (char *)directory, ".");
    tar_close(tar);
    return 0;
}

crashes, but it worked before (in F11 and older rawhide)
the crash is this:

[danny@rawhide ca]$ ./create_archive xx.tar ~/ca
*** buffer overflow detected ***: ./create_archive terminated
======= Backtrace: =========
/lib/libc.so.6(__fortify_fail+0x4d)[0x21d70d]
/lib/libc.so.6[0x21b79a]
/lib/libc.so.6(__strncpy_chk+0x176)[0x21ad86]
/usr/lib/libtar.so.1(th_finish+0x4a)[0x64f56a]
/usr/lib/libtar.so.1(th_write+0x388)[0x64ecf8]
/usr/lib/libtar.so.1(tar_append_file+0x1a0)[0x64e380]
/usr/lib/libtar.so.1(tar_append_tree+0x54)[0x651db4]
./create_archive[0x8048bd5]
./create_archive[0x8048ed7]
./create_archive[0x8048f62]
/lib/libc.so.6(__libc_start_main+0xe6)[0x13cb36]
./create_archive[0x80489a1]
======= Memory map: ========
00102000-00122000 r-xp 00000000 fd:00 188536     /lib/ld-2.10.90.so
00122000-00123000 r--p 0001f000 fd:00 188536     /lib/ld-2.10.90.so
00123000-00124000 rw-p 00020000 fd:00 188536     /lib/ld-2.10.90.so
00126000-0029a000 r-xp 00000000 fd:00 188569     /lib/libc-2.10.90.so
0029a000-0029b000 ---p 00174000 fd:00 188569     /lib/libc-2.10.90.so
0029b000-0029d000 r--p 00174000 fd:00 188569     /lib/libc-2.10.90.so
0029d000-0029e000 rw-p 00176000 fd:00 188569     /lib/libc-2.10.90.so
0029e000-002a1000 rw-p 00000000 00:00 0 
0040d000-0040e000 r-xp 00000000 00:00 0          [vdso]
004a1000-004b1000 r-xp 00000000 fd:00 188894     /lib/libbz2.so.1.0.4
004b1000-004b2000 rw-p 00010000 fd:00 188894     /lib/libbz2.so.1.0.4
0064c000-00654000 r-xp 00000000 fd:00 34056      /usr/lib/libtar.so.1.2.11
00654000-00655000 rw-p 00008000 fd:00 34056      /usr/lib/libtar.so.1.2.11
00655000-00657000 rw-p 00000000 00:00 0 
00726000-00738000 r-xp 00000000 fd:00 188652     /lib/libz.so.1.2.3
00738000-00739000 rw-p 00011000 fd:00 188652     /lib/libz.so.1.2.3
0095f000-00969000 r-xp 00000000 fd:00 39468      /usr/lib/libzip.so.1.0.0
00969000-0096a000 rw-p 00009000 fd:00 39468      /usr/lib/libzip.so.1.0.0
00d72000-00d9c000 r-xp 00000000 fd:00 188576     /lib/libgcc_s-4.4.1-20090725.so.1
00d9c000-00d9d000 rw-p 00029000 fd:00 188576     /lib/libgcc_s-4.4.1-20090725.so.1
00edf000-00eea000 r-xp 00000000 fd:00 188685     /lib/libnss_files-2.10.90.so
00eea000-00eeb000 r--p 0000a000 fd:00 188685     /lib/libnss_files-2.10.90.so
00eeb000-00eec000 rw-p 0000b000 fd:00 188685     /lib/libnss_files-2.10.90.so
08048000-0804a000 r-xp 00000000 fd:00 314441     /home/danny/ca/create_archive
0804a000-0804b000 rw-p 00001000 fd:00 314441     /home/danny/ca/create_archive
09816000-09837000 rw-p 00000000 00:00 0          [heap]
b7ee4000-b7ee6000 rw-p 00000000 00:00 0 
b7f01000-b7f02000 rw-p 00000000 00:00 0 
bf963000-bf978000 rw-p 00000000 00:00 0          [stack]
Aborted (core dumped)

Version-Release number of selected component (if applicable):
libtar-1.2.11-14.fc12.i686

How reproducible:
always

Steps to Reproduce:
1. compile the program in the attachment ("make")
2. run it ("./create_archive foo.tar some_dir/")
3. watch the crash
  
Actual results:
crash, seen above

Expected results:
tar archive to be created

Additional info:
there's a little annoyance, that the char * parameters with path and filename are not const char *, so I have to do this ugly typecast. this isn't worth bugzilla entry by itself, but as I'm already creating one, I can mention that as well