Fix ‘format’ bug with property offsets

* src/editfns.c (styled_format): Fix recently-introduced ‘format’
bug in calculating string property offsets (Bug#21351).

diff --git a/src/editfns.c b/src/editfns.c
index 9db4d9328a0af8ee477607bc4459b9b3735c1523..bbb139f29802e724bb649b6709d0df3a3de433ff 100644 (file)
--- a/src/editfns.c
+++ b/src/editfns.c
@@ -4013,10 +4013,14 @@ styled_format (ptrdiff_t nargs, Lisp_Object *args, bool message)
            error ("Format string ends in middle of format specifier");
 
          memset (&discarded[format0 - format_start], 1, format - format0);
-         conversion = *format++;
+         conversion = *format;
          if (conversion == '%')
-           goto copy_char;
+           {
+             format++;
+             goto copy_char;
+           }
          discarded[format - format_start] = 1;
+         format++;
 
          ++n;
          if (! (n < nargs))