import from branch_1_1:

	try_dlopen() has a bug: it sometimes returns a handle if a dependency
	library can't be loaded.  It also returns an error status, however
	lt_dlopenext() doesn't handle this well and returns the invalid handle.
	This causes a segfault instead of a graceful exit.  Update ltdl to
	give an error telling the user to report the problem, so that we can
	try to reproduce it and report to the libtool folks.  We could just
	leave ltdl unpatched; FR will exit either way.

diff --cc libltdl/ltdl.c
index 57c2a39,889f05d..5fa663b
--- 1/libltdl/ltdl.c
--- 2/libltdl/ltdl.c
+++ b/libltdl/ltdl.c
@@@ -3500,6 -3502,6 +3500,10 @@@ lt_dlopenext (filename
      LT_DLMUTEX_SETERROR (LT_DLSTRERROR (FR_DEPLIB));
      return 0; /* leaks tmp and handle */
    }
++  if (handle && errors) {
++    LT_DLMUTEX_SETERROR (LT_DLSTRERROR (FR_DEPLIB));
++    return 0; /* leaks tmp and handle */
++  }
  
    /* If we found FILENAME, stop searching -- whether we were able to
       load the file as a module or not.  If the file exists but loading
@@@ -3526,6 -3528,6 +3530,10 @@@
    else
      {
        tmp[len] = LT_EOS_CHAR;
++  if (handle && errors) {
++    LT_DLMUTEX_SETERROR (LT_DLSTRERROR (FR_DEPLIB));
++    return 0; /* leaks tmp and handle */
++  }
      }
  
    strcat(tmp, shlib_ext);