fixed lexing (syntax highlighting) of the null-character (^@) in SciTECO code

* Apparently g_utf8_get_char_validated() sometimes(!) returns -2 for null-characters,
  so it was considered an invalid byte sequence.
* What's strange and unexplainable is that other uses of the function, as are behind nA and nQq,
  did not cause problems and returned 0 for null-bytes.
* This also fixes syntax higlighting of .teco_session files which use the null-byte as the
  string terminator.
  (.teco_session files are not highlighted automatically, though.)

1 files changed, 1 insertions, 1 deletions

diff --git a/src/qreg.c b/src/qreg.c
index 91ee630..271e7cb 100644
--- a/src/qreg.c
+++ b/src/qreg.c
@@ -539,7 +539,7 @@ teco_qreg_external_get_character(teco_qreg_t *qreg, teco_int_t position,
 	 * The sign bit in UCS-4/UTF-32 is unused, so this will even
 	 * suffice if TECO_INTEGER == 32.
 	 */
-	*chr = (gint32)g_utf8_get_char_validated(p, -1);
+	*chr = *p ? (gint32)g_utf8_get_char_validated(p, -1) : 0;
 	return TRUE;
 }