From: Paul Eggert Date: Thu, 23 Jan 2014 17:59:46 +0000 (-0800) Subject: Document 2014-01-22T19:02:41Z!eggert@cs.ucla.edu better. X-Git-Tag: emacs-24.3.90~173^2^2~42^2~45^2~276 X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=6c9cbdf04f11b7799ccaef817a5cc79fe6dac02c;p=emacs.git Document 2014-01-22T19:02:41Z!eggert@cs.ucla.edu better. --- diff --git a/lib-src/ChangeLog b/lib-src/ChangeLog index 6f4f3cd86e3..88c30989c75 100644 --- a/lib-src/ChangeLog +++ b/lib-src/ChangeLog @@ -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 (lock_file): Fix test for out-of-date lock file; it was reversed.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