1 files changed, 14 insertions, 1 deletions

diff --git a/src/coding.c b/src/coding.c
index 155da568007..478e119c003 100644
--- a/src/coding.c
+++ b/src/coding.c
@@ -363,6 +363,7 @@ Lisp_Object Qno_conversion, Qundecided;
 Lisp_Object Qcoding_system_history;
 Lisp_Object Qsafe_chars;
 Lisp_Object Qvalid_codes;
+Lisp_Object Qascii_incompatible;
 
 extern Lisp_Object Qinsert_file_contents, Qwrite_region;
 Lisp_Object Qcall_process, Qcall_process_region;
@@ -3625,7 +3626,10 @@ setup_coding_system (coding_system, coding)
         = CODING_REQUIRE_DECODING_MASK | CODING_REQUIRE_ENCODING_MASK;
     }
   else
-    coding->eol_type = CODING_EOL_LF;
+    {
+      coding->common_flags = 0;
+      coding->eol_type = CODING_EOL_LF;
+    }
 
   coding_type = XVECTOR (coding_spec)->contents[0];
   /* Try short cut.  */
@@ -3685,6 +3689,12 @@ setup_coding_system (coding_system, coding)
   if (!NILP (val))
     coding->composing = COMPOSITION_NO;
 
+  /* If the coding system is ascii-incompatible, record it in
+     common_flags.   */
+  val = Fplist_get (plist, Qascii_incompatible);
+  if (! NILP (val))
+    coding->common_flags |= CODING_ASCII_INCOMPATIBLE_MASK;
+
   switch (XFASTINT (coding_type))
     {
     case 0:
@@ -7814,6 +7824,9 @@ syms_of_coding ()
   Qvalid_codes = intern ("valid-codes");
   staticpro (&Qvalid_codes);
 
+  Qascii_incompatible = intern ("ascii-incompatible");
+  staticpro (&Qascii_incompatible);
+
   Qemacs_mule = intern ("emacs-mule");
   staticpro (&Qemacs_mule);