* src/marker.c (buf_bytepos_to_charpos): Re-add the CHAR_HEAD_P assertion

This assertion was removed in 1c349c62305d432abf0fa2b6e3f5d754fe4cab79
because the assumption was invalid during set_intervals_multibyte_1.
So we change set_intervals_multibyte_1 to solve the problem in the same
way as in the rest of Fset_buffer_multibyte, which actually simplifies
the code.

* src/buffer.c (advance_to_char_boundary): Not static any more.
* src/buffer.h (advance_to_char_boundary): Add prototype.
* src/intervals.c (set_intervals_multibyte_1): Use it.

1 files changed, 4 insertions, 1 deletions

diff --git a/src/buffer.c b/src/buffer.c
index ab477481912..3b5078a175b 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -2264,7 +2264,7 @@ validate_region (register Lisp_Object *b, register Lisp_Object *e)
 /* Advance BYTE_POS up to a character boundary
    and return the adjusted position.  */
 
-static ptrdiff_t
+ptrdiff_t
 advance_to_char_boundary (ptrdiff_t byte_pos)
 {
   int c;
@@ -2702,6 +2702,9 @@ current buffer is cleared.  */)
 
       /* Do this last, so it can calculate the new correspondences
          between chars and bytes.  */
+      /* FIXME: Is it worth the trouble, really?  Couldn't we just throw
+         away all the text-properties instead of trying to guess how
+         to adjust them?  AFAICT the result is not reliable anyway.  */
       set_intervals_multibyte (1);
     }