* doc/lispref/text.texi (Undo):
Document (t . 0) and (t . -1) in buffer-undo-list.
* etc/NEWS: Changes to visited-file-modtime, set-visited-file-modtime.
* lisp/files.el (clear-visited-file-modtime): Move here from fileio.c.
* src/atimer.c (schedule_atimer):
* src/fileio.c (Ffile_newer_than_file_p):
Minor cleanup: use EMACS_TIME_LT so that we can remove EMACS_TIME_GT.
* src/buffer.c (buffer-undo-list): Document (t . 0) and (t . -1).
* src/fileio.c (Fclear_visited_file_modtime): Move to lisp/files.el.
(syms_of_fileio): Remove Sclear_visited_file_name.
(Fvisited_file_modtime): Return -1, not (-1 ...), when the visited
file doesn't exist; this avoids an ambiguity with negative timestamps.
(Fset_visited_file_modtime): Accept -1 and 0 as time-list arg.
* src/systime.h (make_emacs_time, invalid_emacs_time):
Don't assume struct timespec layout; POSIX doesn't guarantee it.
(EMACS_TIME_NE, EMACS_TIME_GT, EMACS_TIME_GE): Remove.
* src/undo.c (record_first_change): Push (visited-file-modtime) onto
undo list rather than reimplementing it by hand, incorrectly.
Fixes: debbugs:14824
This directory contains source code for the parts of Emacs that are
written in Emacs Lisp. *.el files are Emacs Lisp source, and the
corresponding *.elc files are byte-compiled versions. Byte-compiled
files are architecture-independent.
The term subdirectory contains Lisp files that customize Emacs for
certain terminal types. When Emacs starts, it checks the TERM
environment variable to get the terminal type and loads
`term/${TERM}.el' if it exists.
The other subdirectories hold Lisp packages grouped by their general
purpose.