2 files changed, 9 insertions, 1 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 3dda03c963f..f46e02b9193 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,8 @@
+2010-09-08  Kenichi Handa  <handa@m17n.org>
+
+        * coding.c (encode_coding_iso_2022): Don't optimize for ASCII if
+        we may use designation or locking-shift.
+
 2010-09-07  Kenichi Handa  <handa@m17n.org>
 
         * coding.c (detect_coding_emacs_mule): Fix checking of multibyte
diff --git a/src/coding.c b/src/coding.c
index d62998f4c8b..92b328091ff 100644
--- a/src/coding.c
+++ b/src/coding.c
@@ -4528,7 +4528,10 @@ encode_coding_iso_2022 (coding)
   charset_list = CODING_ATTR_CHARSET_LIST (attrs);
   coding->safe_charsets = SDATA (CODING_ATTR_SAFE_CHARSETS (attrs));
 
-  ascii_compatible = ! NILP (CODING_ATTR_ASCII_COMPAT (attrs));
+  ascii_compatible
+    = (! NILP (CODING_ATTR_ASCII_COMPAT (attrs))
+       && ! (CODING_ISO_FLAGS (coding) & (CODING_ISO_FLAG_DESIGNATION
+                                          | CODING_ISO_FLAG_LOCKING_SHIFT)));
 
   while (charbuf < charbuf_end)
     {