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t0006 & t5000: prepare for 64-bit timestamps

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Git's source code refers to timestamps as unsigned longs. On 32-bit
platforms, as well as on Windows, unsigned long is not large enough to
capture dates that are "absurdly far in the future".

It is perfectly valid by the C standard, of course, for the `long` data
type to refer to 32-bit integers. That is why the `time_t` data type
exists: so that it can be 64-bit even if `long` is 32-bit. Git's source
code simply uses an incorrect data type for timestamps, is all.

The earlier quick fix 6b9c38e14c (t0006: skip "far in the future" test
when unsigned long is not long enough, 2016-07-11) papered over this
issue simply by skipping the respective test cases on platforms where
they would fail due to the data type in use.

This quick fix, however, tests for *long* to be 64-bit or not. What we
need, though, is a test that says whether *whatever data type we use for
timestamps* is 64-bit or not.

The same quick fix was used to handle the similar problem where Git's
source code uses `unsigned long` to represent size, instead of `size_t`,
conflating the two issues.

So let's just add another prerequisite to test specifically whether
timestamps are represented by a 64-bit data type or not. Later, after we
switch to a larger data type, we can flip that prerequisite to test
`time_t` instead of `long`.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Johannes Schindelin
2017-04-20 22:52:13 +02:00
committed by Junio C Hamano
parent e467dc148d
commit a07fb0507f
4 changed files with 11 additions and 6 deletions
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5
t/helper/test-date.c
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@ -4,7 +4,8 @@ static const char *usage_msg = "\n"
" test-date relative [time_t]...\n"
" test-date show:<format> [time_t]...\n"
" test-date parse [date]...\n"
" test-date approxidate [date]...\n";
" test-date approxidate [date]...\n"
" test-date is64bit\n";
static void show_relative_dates(const char **argv, struct timeval *now)
{
@ -93,6 +94,8 @@ int cmd_main(int argc, const char **argv)
parse_dates(argv+1, &now);
else if (!strcmp(*argv, "approxidate"))
parse_approxidate(argv+1, &now);
else if (!strcmp(*argv, "is64bit"))
return sizeof(unsigned long) == 8 ? 0 : 1;
else
usage(usage_msg);
return 0;