* fhandler.h (class fhandler_dev_clipboard): Remove member eof.

	* fhandler_clipboard.cc: Throughout remove handling of eof member.
	(fhandler_dev_clipboard::write): Handle EOF condition immediately,
	rather than pushing it erroneously to the next read call.  Rearrange
	code.  Fix bug in CF_UNICODETEXT case which potentially dropped single
	bytes at the end of the buffer.  Add comment.
	* strfuncs.cc (sys_cp_wcstombs): Allow returning non-NUL-terminated
	buffer if dst != NULL and len == (size_t) -1.  Extend leading comment
	to explain what's returned in more detail.

1 files changed, 18 insertions, 4 deletions

diff --git a/winsup/cygwin/strfuncs.cc b/winsup/cygwin/strfuncs.cc
index 467f54e87..22ba4d619 100644
--- a/winsup/cygwin/strfuncs.cc
+++ b/winsup/cygwin/strfuncs.cc
@@ -393,9 +393,23 @@ __big5_mbtowc (struct _reent *r, wchar_t *pwc, const char *s, size_t n,
      sequence in by treating it as an UTF-8 char.  If that fails, the ASCII
      CAN was probably standalone and it gets just copied over as ASCII CAN.
 
-   - The functions always create 0-terminated results, no matter what.
-     If the result is truncated due to buffer size, it's a bug in Cygwin
-     and the buffer in the calling function should be raised. */
+   - Three cases have to be distinguished for the return value:
+
+     - dst == NULL; len is ignored, the return value is the number of bytes
+       required for the string without the trailing NUL, just like the return
+       value of the wcstombs function.
+
+     - dst != NULL, len == (size_t) -1; the return value is the size in bytes
+       of the destination string without the trailing NUL.  If the incoming
+       wide char string was not NUL-terminated, the target string won't be
+       NUL-terminated either.
+
+     - dst != NULL; len != (size_t) -1; the return value is the size in bytes
+       of the destination string without the trailing NUL.  The target string
+       will be NUL-terminated, no matter what.  If the result is truncated due
+       to buffer size, it's a bug in Cygwin and the buffer in the calling
+       function should be raised.
+*/
 size_t __stdcall
 sys_cp_wcstombs (wctomb_p f_wctomb, const char *charset, char *dst, size_t len,
 		 const wchar_t *src, size_t nwc)
@@ -473,7 +487,7 @@ sys_cp_wcstombs (wctomb_p f_wctomb, const char *charset, char *dst, size_t len,
       else
 	break;
     }
-  if (n && dst)
+  if (n && dst && len != (size_t) -1)
     {
       n = (n < len) ? n : len - 1;
       dst[n] = '\0';