djdev64: fix emu_dlmopen()

It wasn't actually working, since glibc checks not only names
but also file inodes. So to really trick it, we need to copy
file. Symlink does not help.

Author: stsp

src/djdev64/djdev64.c

@@ -127,6 +127,15 @@ static char *findmnt(const char *path)
 
 static const char *var_list[] = { "_crt0_startup_flags", NULL };
 
+static int cp(const char *from, const char *to)
+{
+    char buf[1024];
+    size_t sz = snprintf(buf, sizeof(buf), "cp %s %s", from, to);
+    if (sz >= sizeof(buf))
+        return -1;
+    return system(buf);
+}
+
 static void *emu_dlmopen(int handle, const char *filename, int flags,
     char **r_path)
 {
@@ -144,9 +153,10 @@ static void *emu_dlmopen(int handle, const char *filename, int flags,
     else
         p++;
     unlink(path);
-    err = symlink(filename, path);
+    /* glibc compares inodes from stat(), so symlinks do not help - use cp */
+    err = cp(filename, path);
     if (err) {
-        perror("symlink()");
+        fprintf(stderr, "cp() failed");
         goto err_free;
     }
     ret = dlopen(path, flags);