Fix BUF_* macros to handle indirect buffers properly (Bug#8219).

* buffer.h (BUF_BEGV, BUF_BEGV_BYTE, BUF_ZV, BUF_ZV_BYTE, BUF_PT)
(BUF_PT_BYTE): Rewrite to handle indirect buffers (Bug#8219).
These macros can no longer be used for assignment.

* buffer.c (Fget_buffer_create, Fmake_indirect_buffer): Assign
struct members directly, instead of using BUF_BEGV etc.
(record_buffer_markers, fetch_buffer_markers): New functions for
recording and fetching special buffer markers.
(set_buffer_internal_1, set_buffer_temp): Use them.

* lread.c (unreadchar): Use SET_BUF_PT_BOTH.

* insdel.c (adjust_point): Use SET_BUF_PT_BOTH.

* intervals.c (temp_set_point_both): Use SET_BUF_PT_BOTH.
(get_local_map): Use SET_BUF_BEGV_BOTH and SET_BUF_ZV_BOTH.

* xdisp.c (hscroll_window_tree):
(reconsider_clip_changes): Use PT instead of BUF_PT.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/lread.c b/src/lread.c
index 8a5f6ecd691..3c5b627f98c 100644
--- a/src/lread.c
+++ b/src/lread.c
@@ -368,15 +368,15 @@ unreadchar (Lisp_Object readcharfun, int c)
   else if (BUFFERP (readcharfun))
     {
       struct buffer *b = XBUFFER (readcharfun);
+      EMACS_INT charpos = BUF_PT (b);
       EMACS_INT bytepos = BUF_PT_BYTE (b);
 
-      BUF_PT (b)--;
       if (! NILP (BVAR (b, enable_multibyte_characters)))
         BUF_DEC_POS (b, bytepos);
       else
         bytepos--;
 
-      BUF_PT_BYTE (b) = bytepos;
+      SET_BUF_PT_BOTH (b, charpos - 1, bytepos);
     }
   else if (MARKERP (readcharfun))
     {