* fns.c (concat): Use STRING_SET_CHARS.

diff --git a/src/fns.c b/src/fns.c
index 217e97ffd56f97969a8656fdc964bac419b1efe9..9874b4dfa48e81e377d3c63573cca886202ea745 100644 (file)
--- a/src/fns.c
+++ b/src/fns.c
@@ -714,7 +714,7 @@ concat (nargs, args, target_type, last_special)
            }
          toindex_byte += thislen_byte;
          toindex += thisleni - combined;
-         SCHARS (val) -= combined;
+         STRING_SET_CHARS (val, SCHARS (val) - combined);
        }
       /* Copy a single-byte string to a multibyte string.  */
       else if (STRINGP (this) && STRINGP (val))
@@ -804,7 +804,7 @@ concat (nargs, args, target_type, last_special)
                        && toindex_byte > 0
                        && count_combining (SDATA (val),
                                            toindex_byte, toindex_byte - 1))
-                     SCHARS (val)--;
+                     STRING_SET_CHARS (val, SCHARS (val) - 1);
                    else
                      toindex++;
                  }