Description of problem:
malloc segfaults if an application calls clearenv() before the first malloc()

Version-Release number of selected component (if applicable):
2.2.93-5

How reproducible:
always

Steps to Reproduce:
1.Compile the following test program:
#include <stdio.h>
#include <stdlib.h>

int main(int argc, char **argv) {

        void *x;
        clearenv();
        x=malloc(100);
        printf("we didn't die\n");
}
2. Run it.
    
Actual results:
Program received signal SIGSEGV, Segmentation fault.
0x420764f6 in ptmalloc_init () from /lib/i686/libc.so.6
(gdb) where
#0  0x420764f6 in ptmalloc_init () from /lib/i686/libc.so.6
#1  0x42076305 in malloc_hook_ini () from /lib/i686/libc.so.6
#2  0x420730f5 in malloc () from /lib/i686/libc.so.6
#3  0x080483c9 in main ()
#4  0x420158d4 in __libc_start_main () from /lib/i686/libc.so.6