(Fformat): Convert an unibyte char argument that is

formatted by "%c" to multibyte if the total result must be a
multibyte string.

1 files changed, 16 insertions, 8 deletions

diff --git a/src/editfns.c b/src/editfns.c
index 6539cd11d45..28c97c11a6b 100644
--- a/src/editfns.c
+++ b/src/editfns.c
@@ -3359,17 +3359,25 @@ usage: (format STRING &rest OBJECTS)  */)
                 error ("Invalid format operation %%%c", *format);
 
             thissize = 30;
-            if (*format == 'c'
-                && (! SINGLE_BYTE_CHAR_P (XINT (args[n]))
-                    || XINT (args[n]) == 0))
+            if (*format == 'c')
               {
-                if (! multibyte)
+                if (! SINGLE_BYTE_CHAR_P (XINT (args[n]))
+                    || XINT (args[n]) == 0)
                   {
-                    multibyte = 1;
-                    goto retry;
+                    if (! multibyte)
+                      {
+                        multibyte = 1;
+                        goto retry;
+                      }
+                    args[n] = Fchar_to_string (args[n]);
+                    thissize = SBYTES (args[n]);
+                  }
+                else if (! ASCII_BYTE_P (XINT (args[n])) && multibyte)
+                  {
+                    args[n]
+                      = Fchar_to_string (Funibyte_char_to_multibyte (args[n]));
+                    thissize = SBYTES (args[n]);
                   }
-                args[n] = Fchar_to_string (args[n]);
-                thissize = SBYTES (args[n]);
               }
           }
         else if (FLOATP (args[n]) && *format != 's')