Bug in lt_dlerror

[John Gruenenfelder]

I think I have found my source of "unknown error" messages in my program.  I
was checking the return value of lt_dlerror() to see if any errors might have
occured.  I believe the autobook says this is a good idea.  And it used to
work too.

The documentation for lt_dlerror() says:
 - Function: const char * lt_dlerror (void)
     Return a human readable string describing the most recent error
     that occurred from any of libltdl's functions.  Return `NULL' if
     no errors have occurred since initialization or since it was last
     called.

I was checking for that NULL return value to make sure no errors had occured.
However, looking at the code in ltdl.c:

const char *
lt_dlerror ()
{
  const char *error;

  LT_DLMUTEX_GETERROR (error);
  LT_DLMUTEX_SETERROR (0);

  return error ? error : LT_DLSTRERROR (UNKNOWN);
}


It seems to me that lt_dlerror() is going to *always* return a non-NULL value,
since LT_DLSTRERROR (UNKNOWN) becomes "unknown error".  That last line should
instead be:

  return error ? error : NULL;


Or am I missing something?


-- 
--John Gruenenfelder    Research Assistant, Steward Observatory, U of Arizona
address@hidden
"This is the most fun I've had without being drenched in the blood
of my enemies!"
        --Sam of Sam & Max