Merge: import mktime and move-if-change fixes from gnulib

1 files changed, 99 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
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+2011-01-30  Paul Eggert  <eggert@cs.ucla.edu>
+
+        gnulib: import mktime and move-if-change fixes from gnulib
+
+        * configure: Regenerate from the following.
+
+        2011-01-30  Paul Eggert  <eggert@cs.ucla.edu>
+
+        mktime: clarify long_int width checking
+        * lib/mktime.c (long_int_is_wide_enough): Move this assertion to
+        the top level, to make it clearer that the assumption about
+        long_int width is being checked.  See
+        <http://lists.gnu.org/archive/html/bug-gnulib/2011-01/msg00554.html>.
+
+        2011-01-29  Paul Eggert  <eggert@cs.ucla.edu>
+
+        TYPE_MAXIMUM: avoid theoretically undefined behavior
+        * lib/intprops.h (TYPE_MINIMUM, TYPE_MAXIMUM): Do not shift a
+        negative number, which the C Standard says has undefined behavior.
+        In practice this is not a problem, but might as well do it by the book.
+        Reported by Rich Felker and Eric Blake; see
+        <http://lists.gnu.org/archive/html/bug-gnulib/2011-01/msg00493.html>.
+        * m4/mktime.m4 (AC_FUNC_MKTIME): Likewise.
+        * lib/mktime.c (TYPE_MAXIMUM): Redo slightly to match the others.
+
+        mktime: #undef mktime before #defining it
+        * lib/mktime.c (mktime) [DEBUG]: #undef mktime before #defining it.
+
+        mktime: systematically normalize tm_isdst comparisons
+        * lib/mktime.c (isdst_differ): New function.
+        (__mktime_internal): Use it systematically for all isdst comparisons.
+        This completes the fix for libc BZ #6723, and removes the need for
+        normalizing tm_isdst.  See
+        <http://sourceware.org/bugzilla/show_bug.cgi?id=6723>
+        (not_equal_tm) [DEBUG]: Use isdst_differ here, too.
+
+        mktime: fix some integer overflow issues and sidestep the rest
+
+        This was prompted by a bug report by Benjamin Lindner for MinGW
+        <http://lists.gnu.org/archive/html/bug-gnulib/2011-01/msg00472.html>.
+        His bug is due to signed integer overflow (0 - INT_MIN), and I
+        I scanned through mktime.c looking for other integer overflow
+        problems, fixing all the bugs I found.
+
+        Although the C Standard says the resulting code is still not safe
+        in the presence of integer overflow, in practice it should be good
+        enough for all real-world two's-complement implementations, except
+        for debugging environments that deliberately trap on integer
+        overflow (e.g., gcc -ftrapv).
+
+        * lib/mktime.c (WRAPV): New macro.
+        (SHR): Also check that long_int and time_t shift right in the
+        usual way, before using the fast-but-unportable method.
+        (TYPE_ONES_COMPLEMENT, TYPE_SIGNED_MAGNITUDE): Remove, no longer
+        used.  The code already assumed two's complement, so there's
+        no need to test for alternatives.  All uses removed.
+        (TYPE_MAXIMUM): Don't rely here on overflow behavior not defined by
+        the C standard.  Problem reported by Rich Felker in
+        <http://lists.gnu.org/archive/html/bug-gnulib/2011-01/msg00488.html>.
+        (twos_complement_arithmetic): Also check long_int and time_t.
+        (time_t_avg, time_t_add_ok, time_t_int_add_ok): New functions.
+        (guess_time_tm, ranged_convert, __mktime_internal): Use them.
+        (__mktime_internal): Avoid integer overflow with unary subtraction
+        in two instances where -1 - X is an adequate replacement for -X,
+        since the calculations are approximate.
+
+        2011-01-29  Eric Blake  <eblake@redhat.com>
+
+        mktime: avoid infinite loop
+        * m4/mktime.m4 (AC_FUNC_MKTIME): Avoid overflow on possibly-signed
+        type; behavior is still undefined but portable to all known targets.
+        Reported by Rich Felker.
+
+        2011-01-28  Paul Eggert  <eggert@cs.ucla.edu>
+
+        mktime: avoid problems on NetBSD 5 / i386
+        * lib/mktime.c (long_int): New type.  This works around a problem
+        on NetBSD 5 / i386, where 'long int' and 'int' are both 32 bits
+        but time_t is 64 bits, and where I expect the existing code is
+        wrong in some cases.
+        (leapyear, ydhms_diff, guess_time_tm, __mktime_internal): Use it.
+        (ydhms_diff): Bring back the compile-time check for wide-enough
+        year and yday.
+
+        mktime: fix misspelling in comment
+        * lib/mktime.c (__mktime_internal): Fix misspelling in comment.
+        This merges all recent glibc changes of importance.
+
+        2011-01-28  Ralf Wildenhues  <Ralf.Wildenhues@gmx.de>
+
+        move-if-change: cope with concurrent mv of identical file.
+        * move-if-change (CMPPROG): Accept environment
+        variable as an override for `cmp'.
+        (usage): Document CMPPROG.
+        Adjust comparison to drop stdout.  Cope with failure of mv if
+        the target file exists and is identical to the source, for
+        parallel builds.
+        Report from H.J. Lu against binutils in PR binutils/12283.
+
 2011-01-29  Eli Zaretskii  <eliz@gnu.org>
 
         * lib/makefile.w32-in: