(scroll_up_aggressively): New.
(scroll_down_aggressively): New.
(struct buffer): indicate_empty_lines renamed from
indicate_zv_lines.
(struct buffer): New member indicate_zv_lines.
(struct buffer): New members left_margin_width
and right_margin_width.
(struct buffer): Add member minibuffer_prompt_length
if PROMPT_IN_BUFFER.
(CHAR_TO_BYTE, BYTE_TO_CHAR): New macros.
(BEG_BYTE, BEGV_BYTE, PT_BYTE, GPT_BYTE)
(ZV_BYTE, Z_BYTE): New macros.
(BUF_BEG_BYTE, BUF_BEGV_BYTE, BUF_PT_BYTE, BUF_GPT_BYTE)
(BUF_ZV_BYTE, BUF_Z_BYTE): New macros.
(BUF_GAP_END_ADDR): New macro.
(BEGV_ADDR, PT_ADDR, GPT_ADDR, GAP_END_ADDR, ZV_ADDR, Z_ADDR):
Use the new ..._byte buffer data.
(BUFFER_CEILING_OF, BUFFER_FLOOR_OF): Likewise.
(BUF_GPT_ADDR, BUF_Z_ADDR): Likewise.
(SET_PT_BOTH, TEMP_SET_PT_BOTH): New macros.
(SET_PT, TEMP_SET_PT, BUF_SET_PT, BUF_TEMP_SET_PT):
Call functions with new arg order.
(SET_BUF_BEGV, SET_BUF_BEGV_BOTH): New macros.
(SET_BUF_PT): Macro deleted.
(SET_BUF_ZV): Set charpos and bytepos.
(SET_BUF_ZV_BOTH, SET_BUF_PT_BOTH): New macros.
(BYTE_POS_ADDR): Renamed from POS_ADDR.
(CHAR_POS_ADDR): New macro.
(FETCH_BYTE): Use BYTE_POS_ADDR.
(FETCH_MULTIBYTE_CHAR): Use ..._BYTE macros.
(BUF_CHAR_ADDRESS): Convert charpos to bytepos.
(BUF_BYTE_ADDRESS): New macro, like the old BUF_CHAR_ADDRESS.
(PTR_BYTE_POS): Renamed from PTR_CHAR_POS.
(BUF_PTR_BYTE_POS): New macro.
(BUF_FETCH_CHAR, BUF_FETCH_BYTE, BUF_FETCH_MULTIBYTE_CHAR): New macros.
(struct buffer_text): New fields gpt_byte, z_byte.
(struct buffer): New fields pt_byte, begv_byte, zv_byte.
(Z_ADDR, BUF_GPT_ADDR, BUF_Z_ADDR): New macros.
(struct buffer): New members `category_table',
`direction_reserved', and `enable-multibyte-characters'.
(POS_ADDR): New macro used at all places instead of &FETCH_CHAR.
(FETCH_BYTE): New macro used at any places to check the argument
against an ASCII character.
(FETCH_MULTIBYTE_CHAR): New macro used at any places to get a
character code of the argument when it is known to be a multibyte
character.
(_fetch_multibyte_char_p, _fetch_multibyte_char_len): New
variables.
(FETCH_CHAR): Use macros FETCH_MULTIBYTE_CHAR and FETCH_BYTE.
(struct buffer_text): Fields markers and intervals moved here.
(BUF_MARKERS, BUF_INTERVALS): New macros.
(struct buffer): Make buffer_file_type field unconditional.
(struct buffer): New field pt_marker.
save_modiff field deleted.
(struct buffer_text): save_modiff field moved here.
(SAVE_MODIFF, BUF_SAVE_MODIFF): New macros.
Use them instead of direct access to save_modiff field.
(struct buffer): New fields begv_marker, zv_marker.
(struct buffer): Make text field be a pointer.
The struct buffer_text field renamed to own_text.
Add fields indirect_to_buffer and size.
Move pt, begv and zv fields here.
(struct buffer_text): Moved from here.
(BEGV, PT, ZV, BEGV_ADDR, PT_ADDR, ZV_ADDR): Corresponding changes.
(BUF_BEGV, BUF_PT, BUF_ZV): Corresponding changes.
(SET_BUF_ZV, SET_BUF_PT, point):
(OVERLAYP): New predicate.
(CHECK_OVERLAY): New type-checker.
(Qoverlayp): New extern declaration.
* buffer.c (Foverlayp): New function.
(Qoverlayp): New atom.
(overlays_at, recenter_overlay_lists): Abort if we encounter an
invalid overlay.
(syms_of_buffer): defsubr Soverlayp; initialize Qoverlayp.
(Fdelete_overlay): Set the overlay's markers to point nowhere.
Use CHECK_OVERLAY instead of signalling a special error.
(Fmove_overlay, Foverlay_put): Use CHECK_OVERLAY instead of
signalling a special error.
(Foverlay_get): Use CHECK_OVERLAY.
* fns.c (internal_equal): Define this for overlays.
* buffer.h (OVERLAY_VALID): Define in terms of OVERLAYP.
* print.c (print): Give overlays their own print syntax.
* alloc.c (mark_object): Treat overlays like conses.
