/***********************************************************************
 * This is a STC to show that fork causes a SEGV after a DLL has been loaded
 * and unloaded.
 *
 * It loads and unloads a test DLL then does a simple fork. This causes a SEGV
 * with 1.7.19-6 (although not with 1.7.19-5). If the DLL is not unloaded then
 * no SEGV occurs.
 *
 * This test was extracted from the APR test suite.
 *
 * To compile and run, just run make. To run the test without unloading the
 * DLL, run "make test-nofail".
 ***********************************************************************/
#include <string.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <dlfcn.h>
#include <errno.h>
#include <sys/wait.h>

int do_unload = 1;

void load_dso ()
{
    char dll[PATH_MAX];
    getcwd(dll, PATH_MAX);
    strcat(dll, "/mod_test.dll");

    void *os_handle = dlopen(dll, RTLD_NOW | RTLD_GLOBAL);
    if (os_handle == NULL) {
        perror("Could not open DLL");
        exit(1);
    }
    if (do_unload) {
        if (dlclose(os_handle) != 0) {
            perror("Could not close DLL");
            exit(1);
        }
    }
}

void do_fork ()
{
    pid_t pid;
    printf("Calling fork()\n"); fflush(stdout);
    if ((pid = fork()) < 0) {
        perror("fork failed");
        exit(1);
    }
    else if (pid == 0) {
        printf("In child\n"); fflush(stdout);
        exit(0);
    }
    else {
        printf("Awaiting child\n"); fflush(stdout);
        // await child
        int exit_int;
        pid_t pstatus;

        do {
            pstatus = waitpid(pid, &exit_int, WUNTRACED);
        } while (pstatus < 0 && errno == EINTR);

        printf("Child finished\n"); fflush(stdout);
    }
}

int main (int argc, const char * const * argv, const char * const *env)
{
    if (argc > 1) {
        do_unload = 0;
    }
    load_dso();
    do_fork();
    return 0;
}