implement LFN support

[stsp]

Commands like dir, copy etc may use lfns.

[rouseabout]

LFN is disabled by default. _CRT0_FLAG_NO_LFN is set in _crt0_startup_flags.

To enable LFN, comment out _CRT0_FLAG_NO_LFN and disable the uppercase conversion in extract_token

diff --git a/command.c b/command.c
index aeea717..42a1651 100644
--- a/command.c
+++ b/command.c
@@ -116,7 +116,7 @@ extern char **environ;
 int _crt0_startup_flags =
        _CRT0_FLAG_USE_DOS_SLASHES |          // keep the backslashes
        _CRT0_FLAG_DISALLOW_RESPONSE_FILES |  // no response files (i.e. `@gcc.rf')
-       _CRT0_FLAG_NO_LFN |                   // disable long file names
+       //_CRT0_FLAG_NO_LFN |                   // disable long file names
        _CRT0_FLAG_LOCK_MEMORY |              // disable virtual memory
        _CRT0_FLAG_PRESERVE_FILENAME_CASE;    // keep DOS names uppercase
 char **__crt0_glob_function(char *_argument UNUSED) {return NULL;} // prevent wildcard expansion of arguments of main()
@@ -2563,6 +2563,11 @@ again:
     advance_iter(iter);
     return tok;
     }
+
+#ifdef __DJGPP__
+  /* only when using NO_LFN should we uppercase the wildcard token */
+  if ((_crt0_startup_flags & _CRT0_FLAG_NO_LFN))
+#endif
   strupr(iter->token);
   if (glob(iter->token, 0, NULL, &iter->gl))
     {

[stsp]

That's interesting. @andrewbird would you like to test that change to make sure it actually passes the LFN tests?

[andrewbird]

Sorry I have no time today, but I don't think any of the tests use LFNs in the shell itself anyway.

[stsp]

Indeed with a minimal testing it appears to work. DIR displays LFNs, COPY copies them properly, no obvious buffer overflows... What else is to desire? :)