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, 31 insertions, 14 deletions

diff --git a/src/buffer.h b/src/buffer.h
index 65c7168d60a..0975d2e3adc 100644
--- a/src/buffer.h
+++ b/src/buffer.h
@@ -107,27 +107,46 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #define BUF_BEG(buf) (BEG)
 #define BUF_BEG_BYTE(buf) (BEG_BYTE)
 
-/* !!!FIXME:  all the BUF_BEGV/BUF_ZV/BUF_PT macros are flawed:
-   on indirect (or base) buffers, that value is only correct if that buffer
-   is the current_buffer, or if the buffer's text hasn't been modified (via
-   an indirect buffer) since it was last current.  */
+/* The BUF_BEGV[_BYTE], BUF_ZV[_BYTE], and BUF_PT[_BYTE] macros cannot
+   be used for assignment; use SET_BUF_* macros below for that.  */
 
 /* Position of beginning of accessible range of buffer.  */
-#define BUF_BEGV(buf) ((buf)->begv)
-#define BUF_BEGV_BYTE(buf) ((buf)->begv_byte)
+#define BUF_BEGV(buf)                                   \
+   (buf == current_buffer ? BEGV                        \
+    : NILP (BVAR (buf, begv_marker)) ? buf->begv        \
+    : marker_position (BVAR (buf, begv_marker)))
+
+#define BUF_BEGV_BYTE(buf)                              \
+   (buf == current_buffer ? BEGV_BYTE                   \
+    : NILP (BVAR (buf, begv_marker)) ? buf->begv_byte   \
+    : marker_byte_position (BVAR (buf, begv_marker)))
 
 /* Position of point in buffer.  */
-#define BUF_PT(buf) ((buf)->pt)
-#define BUF_PT_BYTE(buf) ((buf)->pt_byte)
+#define BUF_PT(buf)                                     \
+   (buf == current_buffer ? PT                          \
+    : NILP (BVAR (buf, pt_marker)) ? buf->pt            \
+    : marker_position (BVAR (buf, pt_marker)))
+
+#define BUF_PT_BYTE(buf)                                \
+   (buf == current_buffer ? PT_BYTE                     \
+    : NILP (BVAR (buf, pt_marker)) ? buf->pt_byte       \
+    : marker_byte_position (BVAR (buf, pt_marker)))
+
+/* Position of end of accessible range of buffer.  */
+#define BUF_ZV(buf)                                     \
+   (buf == current_buffer ? ZV                          \
+    : NILP (BVAR (buf, zv_marker)) ? buf->zv            \
+    : marker_position (BVAR (buf, zv_marker)))
+
+#define BUF_ZV_BYTE(buf)                                \
+   (buf == current_buffer ? ZV_BYTE                     \
+    : NILP (BVAR (buf, zv_marker)) ? buf->zv_byte       \
+    : marker_byte_position (BVAR (buf, zv_marker)))
 
 /* Position of gap in buffer.  */
 #define BUF_GPT(buf) ((buf)->text->gpt)
 #define BUF_GPT_BYTE(buf) ((buf)->text->gpt_byte)
 
-/* Position of end of accessible range of buffer.  */
-#define BUF_ZV(buf) ((buf)->zv)
-#define BUF_ZV_BYTE(buf) ((buf)->zv_byte)
-
 /* Position of end of buffer.  */
 #define BUF_Z(buf) ((buf)->text->z)
 #define BUF_Z_BYTE(buf) ((buf)->text->z_byte)
@@ -235,8 +254,6 @@ extern void enlarge_buffer_text (struct buffer *, EMACS_INT);
 
 /* Macros for setting the BEGV, ZV or PT of a given buffer.
 
-   SET_BUF_PT* seet to be redundant.  Get rid of them?
-
    The ..._BOTH macros take both a charpos and a bytepos,
    which must correspond to each other.