Timestamp fixes for undo.

* 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

1 files changed, 18 insertions, 0 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index a96f1153ef0..049c917eddd 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,21 @@
+2013-07-10  Paul Eggert  <eggert@cs.ucla.edu>
+
+        Timestamp fixes for undo (Bug#14824).
+        * atimer.c (schedule_atimer):
+        * fileio.c (Ffile_newer_than_file_p):
+        Minor cleanup: use EMACS_TIME_LT so that we can remove EMACS_TIME_GT.
+        * buffer.c (buffer-undo-list): Document (t . 0) and (t . -1).
+        * 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.
+        * 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.
+        * undo.c (record_first_change): Push (visited-file-modtime) onto
+        undo list rather than reimplementing it by hand, incorrectly.
+
 2013-07-09  Ken Brown  <kbrown@cornell.edu>
 
         * sheap.c (STATIC_HEAP_SIZE) [__x86_64__]: Increase to 18MB.