[Emacs-diffs] trunk r116131: Document trunk bzr 116113 better.

[Paul Eggert]

------------------------------------------------------------
revno: 116131
revision-id: address@hidden
parent: address@hidden
committer: Paul Eggert <address@hidden>
branch nick: trunk
timestamp: Thu 2014-01-23 09:59:46 -0800
message:
  Document trunk bzr 116113 better.
modified:
  lib-src/ChangeLog              changelog-20091113204419-o5vbwnq5f7feedwu-1608

=== modified file 'lib-src/ChangeLog'
--- a/lib-src/ChangeLog 2014-01-22 19:38:31 +0000
+++ b/lib-src/ChangeLog 2014-01-23 17:59:46 +0000
@@ -7,13 +7,27 @@
 
        Fix miscellaneous update-game-score bugs.
        * update-game-score.c (difftime) [!HAVE_DIFFTIME]: Remove.
-       (read_score) [HAVE_GETDELIM]: Don't access uninitialized storage.
-       (read_scores, write_scores): Check for fclose failure.
+       (read_score) [HAVE_GETDELIM]: Don't access uninitialized storage,
+       as that leads to undefined behavior, which is a bad thing
+       particularly in a setuid program.
+       (read_scores, write_scores): Check for fclose failure; on some
+       systems, I/O errors are not reported by primitives like getc and
+       putc, but instead are delayed until fclose, so fclose failures
+       should be diagnosed like other read and write errors.
        (write_scores): Use fchmod, not chmod, to avoid a race.
+       Otherwise, if the lock is broken by some other process,
+       update-game-score might try to change the permission on someone
+       else's file or on a nonexistent file, and incorrectly report an
+       error when this fails.
        (lock_file): Fix test for out-of-date lock file; it was reversed.
-       Use ordinary subtraction rather than difftime; since we're already
-       assuming POSIX we don't need to worry about the possibility of
-       time_t being a magic cookie.
+       That is, it incorrectly broke locks when they were more than an
+       hour into the future, instead of when they were more than an hour
+       in the past.  Use ordinary subtraction rather than difftime; since
+       we're already assuming POSIX we don't need to worry about the
+       possibility of time_t being a magic cookie, and since timestamps
+       are positive we don't need to worry about integer overflow when
+       subtracting them.  Put two spaces, not just one, after a sentence
+       end in a comment.
 
 2014-01-19  Paul Eggert  <address@hidden>