1 files changed, 9 insertions, 5 deletions

diff --git a/src/xdisp.c b/src/xdisp.c
index dbce1c56368..306e26702f5 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -7976,7 +7976,7 @@ store_frame_title (str, field_width, precision)
 
   /* Copy at most PRECISION chars from STR.  */
   nbytes = strlen (str);
-  n+= c_string_width (str, nbytes, precision, &dummy, &nbytes);
+  n += c_string_width (str, nbytes, precision, &dummy, &nbytes);
   while (nbytes--)
     store_frame_title_char (*str++);
 
@@ -15457,14 +15457,15 @@ display_mode_element (it, depth, field_width, precision, elt, props, risky)
 
             if (this - 1 != last)
               {
+                int nchars, nbytes;
+
                 /* Output to end of string or up to '%'.  Field width
                    is length of string.  Don't output more than
                    PRECISION allows us.  */
                 --this;
 
-                prec = chars_in_text (last, this - last);
-                if (precision > 0 && prec > precision - n)
-                  prec = precision - n;
+                prec = c_string_width (last, this - last, precision - n,
+                                       &nchars, &nbytes);
 
                 if (frame_title_ptr)
                   n += store_frame_title (last, 0, prec);
@@ -15472,9 +15473,12 @@ display_mode_element (it, depth, field_width, precision, elt, props, risky)
                   {
                     int bytepos = last - lisp_string;
                     int charpos = string_byte_to_char (elt, bytepos);
+                    int endpos = (precision <= 0 ? SCHARS (elt)
+                                  : charpos + nchars);
+
                     n += store_mode_line_string (NULL,
                                                  Fsubstring (elt, make_number (charpos),
-                                                             make_number (charpos + prec)),
+                                                             make_number (endpos)),
                                                  0, 0, 0, Qnil);
                   }
                 else