Description of problem:
Symbol lookup in elf/dl-lookup.c (dl_lookup_x) incorrectly handles combination of STB_GNU_UNIQUE binding and ELF_RTYPE_CLASS_COPY relocation resulting in returning wrong values, leading to copy relocation effectively not being made.

This bug was reported earlier was fixed in glibc-2.13
https://sourceware.org/bugzilla/show_bug.cgi?id=12510

Version-Release number of selected component (if applicable):
Red Hat Enterprise Linux 6.4
glibc-2.12-1.107.el6_4.4.x86_64

How reproducible:
Always

Steps to Reproduce:

$ cat lib.h
template<typename T> struct S {
    static int i;
};


$ cat lib.cc
#include "lib.h"
template<typename T> int S<T>::i = 1;
static int i = S<char>::i;


$ cat test.cc
#include "lib.h"
#include <cstdio>
int main() {
    std::printf("%d\n", S<char>::i);
    return 0;
}

$ gcc -shared -fPIC -o lib.so lib.cc
$ gcc -o test test.cc lib.so -lstdc++

Actual results:
$ LD_LIBRARY_PATH=. ./test
0

Expected results:
$ LD_LIBRARY_PATH=. ./test
1

Additional info:
This issue was reported by our customer. The test cases performed at their end are attached.

I have tested the patch at my end by rebuilding glibc and could find that the patch fixes the issue.

# Without patch
/lib64/ld-linux-x86-64.so.2 --library-path .:/lib64:/usr/lib64 ./test
0

# With patch included
/opt/glibc/lib64/ld-linux-x86-64.so.2 --library-path .:/lib64:/usr/lib64 ./test
1

The patch is also attached to this bug report.