(CHARS_MODIFF, BUF_CHARS_MODIFF): New macros.
* buffer.c (Fbuffer_chars_modified_tick): New function returning
value of BUF_CHARS_MODIFF.
(syms_of_buffer): Defsubr it.
(Fget_buffer_create): Initialize BUF_CHARS_MODIFF.
* insdel.c (modify_region): New argument preserve_chars_modiff.
Set CHARS_MODIFF to MODIFF provided preserve_chars_modiff is zero.
(insert_1_both, insert_from_string_1, insert_from_buffer_1)
(adjust_after_replace, adjust_after_replace_noundo)
(replace_range, replace_range_2, del_range_2): Reset CHARS_MODIFF.
* lisp.h (modify_region): Add fourth argument in extern.
* casefiddle.c (casify_region): Call modify_region with fourth
argument zero to assert that CHARS_MODIFF is updated.
* editfns.c (Fsubst_char_in_region, Ftranslate_region_internal)
(Ftranspose_regions): Likewise.
* textprop.c (Fadd_text_properties, Fset_text_properties)
(Fremove_text_properties, Fremove_list_of_text_properties):
Call modify_region with fourth argument 1 to avoid that
CHARS_MODIFF is updated.
is exhausted, return with RET.
(detect_coding_emacs_mule, detect_coding_iso2022)
(detect_coding_sjis, detect_coding_big5, detect_coding_utf_8)
(detect_coding_utf_16, detect_coding_ccl): Adjusted for the above
change.
(syms_of_xselect): Defsubr it.
(x_handle_dnd_message): Check that message_type is in
dpyinfo->x_dnd_atoms before generating lisp event.
* xterm.h (struct x_display_info): Add x_dnd_atoms* to keep track
of drag and drop Atoms.
* xterm.c (x_term_init): Initialize dpyinfo->x_dnd_atoms*
(input_available_signal): Set in_sighandler.
(init_keyboard): Initialize in_sighandler.
* keyboard.h: Declare in_sighandler.
* alloc.c (UNBLOCK_INPUT_ALLOC, BLOCK_INPUT_ALLOC): Use in_sighandler
to check if mutex should be locked or not.
