(lisp_string_width): Check multibyteness of STRING.

1 files changed, 21 insertions, 13 deletions

diff --git a/src/character.c b/src/character.c
index 91b889c3836..8f6eda9c91e 100644
--- a/src/character.c
+++ b/src/character.c
@@ -442,6 +442,10 @@ lisp_string_width (string, precision, nchars, nbytes)
      int precision, *nchars, *nbytes;
 {
   int len = SCHARS (string);
+  /* This set multibyte to 0 even if STRING is multibyte when it
+     contains only ascii and eight-bit-graphic, but that's
+     intentional.  */
+  int multibyte = len < SBYTES (string);
   unsigned char *str = SDATA (string);
   int i = 0, i_byte = 0;
   int width = 0;
@@ -462,23 +466,27 @@ lisp_string_width (string, precision, nchars, nbytes)
           chars = end - i;
           bytes = string_char_to_byte (string, end) - i_byte;
         }
-      else if (dp)
-        {
-          int c = STRING_CHAR_AND_LENGTH (str + i_byte, len - i_byte, bytes);
-
-          chars = 1;
-          val = DISP_CHAR_VECTOR (dp, c);
-          if (VECTORP (val))
-            thiswidth = XVECTOR (val)->size;
-          else
-            thiswidth = CHAR_WIDTH (c);
-        }
       else
         {
-          int c = STRING_CHAR_AND_LENGTH (str + i_byte, len - i_byte, bytes);
+          int c;
 
+          if (multibyte)
+            c = STRING_CHAR_AND_LENGTH (str + i_byte, len - i_byte, bytes);
+          else
+            c = str[i_byte], bytes = 1;
           chars = 1;
-          thiswidth = CHAR_WIDTH (c);
+          if (dp)
+            {
+              val = DISP_CHAR_VECTOR (dp, c);
+              if (VECTORP (val))
+                thiswidth = XVECTOR (val)->size;
+              else
+                thiswidth = CHAR_WIDTH (c);
+            }
+          else
+            {
+              thiswidth = CHAR_WIDTH (c);
+            }
         }
 
       if (precision > 0