This essentially folds compat_symbol_unique functionality into
compat_symbol.
This change eliminates the need for intermediate aliases for defining
multiple symbol versions, for both compat_symbol and versioned_symbol.
Some binutils versions do not suport multiple versions per symbol on
some targets, so aliases are automatically introduced, similar to what
compat_symbol_unique did. To reduce symbol table sizes, a configure
check is added to avoid these aliases if they are not needed.
The new mechanism works with data symbols as well as function symbols,
due to the way an assembler-level redirect is used. It is not
compatible with weak symbols for old binutils versions, which is why
the definition of __malloc_initialize_hook had to be changed. This
is not a loss of functionality because weak symbols do not matter
to dynamic linking.
The placeholder symbol needs repeating in nptl/libpthread-compat.c
now that compat_symbol is used, but that seems more obvious than
introducing yet another macro.
A subtle difference was that compat_symbol_unique made the symbol
global automatically. compat_symbol does not do this, so static
had to be removed from the definition of
__libpthread_version_placeholder.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This code brings test to check if time on target machine is properly set.
To avoid any issues with altering the time:
- The time, which was set before the test was executed is restored.
- The time is altered only when cross-test-ssh.sh is executed with
--allow-time-setting flag
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This code brings test to check if time on target machine is properly set.
To avoid any issues with altering the time:
- The time, which was set before the test was executed is restored.
- The time is altered only when cross-test-ssh.sh is executed with
--allow-time-setting flag
Reviewed-by: DJ Delorie <dj@redhat.com>
This change adds new test to assess mktime's functionality.
To be more specific - following use cases are checked:
- Pass struct tm as epoch time
- Pass struct tm as value just before Y2038 threshold (returned
value shall be 0x7FFFFFFF)
- Pass struct tm as the first value after Y2038 threshold
(expected value - 0x80000000)
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This change adds new test to assess difftime's functionality by
adding some arbitrary offsets to current time_t value (read via
time).
If 64 bit time_t is supported, the same procedure is applied around
the threshold of Y2038 time overflow.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This change adds new test to assess ctime's functionality.
To be more specific - following use cases are checked:
- Pass time_t value as 0 to check if epoch time is converted
- Pass time_t as max value for 32 bit systems
- Pass time_t as the first value after Y2038 threshold
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
I used these shell commands:
../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")
and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 6694 files FOO.
I then removed trailing white space from benchtests/bench-pthread-locks.c
and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this
diagnostic from Savannah:
remote: *** pre-commit check failed ...
remote: *** error: lines with trailing whitespace found
remote: error: hook declined to update refs/heads/master
The adjtime interface allows return the amount of time remaining
from any previous adjustment that has not yet been completed by
passing a NULL as first argument. This was introduced with y2038
support 0308077e3a.
Checked on i686-linux-gnu.
Reviewed-by: Lukasz Majewski <lukma@denx.de>
It does not provide __clock_gettime64, the ftime y2038 support is
moved to a Linux specific implementation.
Checked with a build for i686-linux-gnu and on x86_64-linux and
i686-linux-gnu.
It basically calls the 64-bit __clock_gettime64 and adds the overflow
check.
Checked on x86_64-linux-gnu and i686-linux-gnu.
Reviewed-by: Lukasz Majewski <lukma@denx.de>
Starting with the commit 04deeaa9ea
"Fix time/tst-cpuclock1 intermitent failures" (2020-07-11),
this test fails quite often on s390x/s390 with one/multiple of those:
"before - after" / "nanosleep time" / "dead - after" ourside reasonable range.
On a zVM/kvm guest the CPUs are shared between multiple guests.
And even on the lpar (kvm host) the CPUs are usually shared between multiple lpars.
The defined CPUs for a lpar/zVM-system could also have lower weights compared
to other lpars which let the steal time further grow.
Usually I build (-j$(nproc)) and test (PARALLELMFLAGS="-j$(nproc)") glibc multiple
times, e.g. with different GCCs, on various lpars or zVM guests at the same time.
During this time, I've run the test for 13500 times and obvserved the following fails:
~600x "before - after"
~60x "nanosleep time"
~70x "dead - after"
I've also observed a lot of "before - after" fails on a intel kvm-guest while
building/testing glibc on it.
The mentioned commit has tighten the limits of valid tv_nsec ranges:
"before - after" (expected: 500000000):
- 100000000 ... 600000000
+ 450000000 ... 550000000
"nanosleep time" (expected: 100000000):
- 100000000 ... 200000000
+ 090000000 ... 120000000
"dead - after" (expected: 100000000):
- ... 200000000
+ 090000000 ... 120000000
The test itself forks a child process which chew_cpu (user- and kernel-space).
The parent process sleeps with nanosleep(0.5s) and measures the child_clock time:
diff = after - before
With much workload on the machine, the child won't make much progess
and it can fall much beyond the minimum limit.
Afterwards the parent process sleeps with clock_nanosleep (child_clock, 0.1s):
diff = afterns - after
The test currently also allows 0.9 * 0.1s which would be an error.
Depending on the workload, the maximum limit can exceed the 1.2 * 0.1s.
For "dead - after", the parent process kills the child process and waits long
enough to let the child finish dying. Then it gets the time of the child:
diff = dead - after
Note that diff also contains the time for the previous clock_nanosleep.
Thus you'll often see both fails at the same time.
After discussion on the mailing list, we've decided to keep the functional
checks for the clock* functions and remove the timing related checks as those
are prone to false positives.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
It was made deprecated on 2.31, so it moves to compat symbol after
two releases. It was also removed from exported symbol for riscv32
(since ABI will be supported on for 2.33).
Checked on x86_64-linux-gnu and i686-linux-gnu.
Reviewed-by: Lukasz Majewski <lukma@denx.de>
It replaces the internal usage of __{f,l}xstat{at}{64} with the
__{f,l}stat{at}{64}. It should not change the generate code since
sys/stat.h explicit defines redirections to internal calls back to
xstat* symbols.
Checked with a build for all affected ABIs. I also check on
x86_64-linux-gnu and i686-linux-gnu.
Reviewed-by: Lukasz Majewski <lukma@denx.de>
This test fails intermittently in systems with heavy load as
CLOCK_PROCESS_CPUTIME_ID is subject to scheduler pressure. Thus the
test boundaries were relaxed to keep it from failing on such systems.
A refactor of the spent time checking was made with some support
functions. With the advantage to representing time jitter in percent
of the target.
The values used by the test boundaries are all empirical.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
This patch updates files coming from tzcode to tzcode 2020a.
This is mostly for better support for Internet RFC 8536, by adding
support to zic for the Expires line (new to tzcode 2020a), the -b
option (new to 2019b) and the -r option (new to 2019a).
One trivial change to other glibc was needed.
* time/tzfile.c (__tzfile_read): Adjust to tzcode private.h renaming.
* timezone/private.h, timezone/tzfile.h, timezone/version:
* timezone/zdump.c, timezone/zic.c: Update from tzcode 2020a.
In the glibc project calls to clock_gettime shall be replaced with
__clock_gettime64, which is supporting 64 bit time.
To allow that the __clock_gettime64 needs to be exported as a GLIBC_PRIVATE
symbol.
By undef strong_alias on alpha implementation, the
default_symbol_version macro becomes an empty macro on static build.
It fixes the issue introduced at c953219420.
Checked on alpha-linux-gnu with a 'make check run-built-tests=no'.
It makes alpha no longer reports information about a system-wide
time zone and moves the version logic on the alpha implementation.
Checked on a build and check-abi for alpha-linux-gnu.
Reviewed-by: Lukasz Majewski <lukma@denx.de>
C2X adds the asctime_r, ctime_r, gmtime_r and localtime_r functions.
This patch duly adds __GLIBC_USE (ISOC2X) to the conditions under
which <time.h> declares them.
Tested for x86_64.
The generic version is straightforward. For Hurd, its nanosleep
implementation is moved to clock_nanosleep with adjustments from
generic unix implementation.
The generic clock_nanosleep unix version is also removed since
it calls nanosleep.
Checked on x86_64-linux-gnu and powerpc64le-linux-gnu.
Reviewed-by: Florian Weimer <fweimer@redhat.com>
Checked on x86_64-linux-gnu and powerpc64le-linux-gnu. I also checked
the libpthread.so .gnu.version_d entries for every ABI affected and
all of them contains the required versions (including for architectures
which exports __nanosleep with a different version).
Reviewed-by: Florian Weimer <fweimer@redhat.com>
Also make the public prototype of gettimeofday declare its second
argument with type "void *" unconditionally, consistent with POSIX.
It is also consistent with POSIX.
Checked on x86_64-linux-gnu, i686-linux-gnu, powerpc64le-linux-gnu,
powerpc64-linux-gnu, powerpc-linux-gnu, and aarch64-linux-gnu.
Co-authored-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Lukasz Majewski <lukma@denx.de>
Consolidate generic gettimeofday implementation to use clock_gettime.
Linux ports that still provide gettimeofday through vDSO are not
changed.
Remove sysdeps/unix/clock_gettime.c, which implemented clock_gettime
using gettimeofday; new OS ports must provide a real implementation of
clock_gettime.
Rename sysdeps/mach/gettimeofday.c to sysdeps/mach/clock_gettime.c and
convert into an implementation of clock_gettime. It only supports
CLOCK_REALTIME; Mach does not appear to have any support for monotonic
clocks. It uses __host_get_time, which provides at best microsecond
resolution. Hurd is currently using sysdeps/posix/clock_getres.c for
clock_getres; its output for CLOCK_REALTIME is based on
sysconf (_SC_CLK_TCK), and I do not know whether that gives the
correct result.
Unlike settimeofday, there are no known uses of gettimeofday's
vestigial "get time zone" feature that are not bugs. (The per-process
timezone support in localtime and friends is unrelated, and the
programs that set the kernel's offset between the hardware clock and
UTC do not need to read it back.) Therefore, this feature is dummied
out. Henceforth, if gettimeofday's "struct timezone" argument is not
NULL, it will write zeroes to both fields. Any program that is
actually looking at this data will thus think it is running in UTC,
which is probably more correct than whatever it was doing before.
[__]gettimeofday no longer has any internal callers, so we can now
remove its internal prototype and PLT bypass aliases. The
__gettimeofday@GLIBC_2.0 export remains, in case it is used by any
third-party code.
It also allows to simplify the arch-specific implementation on x86 and
powerpc to remove the hack to disable the internal route to non iFUNC
variant for internal symbol.
This patch also fixes a missing optimization on aarch64, powerpc, and
x86 where the code used on static build do not use the vDSO.
Checked on x86_64-linux-gnu, i686-linux-gnu, powerpc64le-linux-gnu,
powerpc64-linux-gnu, powerpc-linux-gnu, and aarch64-linux-gnu.
Co-authored-by: Zack Weinberg <zackw@panix.com>
Reviewed-by: Lukasz Majewski <lukma@denx.de>
timespec_get is the same function as clock_gettime, with an obnoxious
coating of NIH painted on it by the ISO C committee. In addition to
the rename, it takes its arguments in a different order, it returns 0
on *failure* or a positive number on *success*, and it requires that
all of its TIME_* constants be positive. This last means we cannot
directly reuse the existing CLOCK_* constants for it, because
those have been allocated starting with CLOCK_REALTIME = 0 on all
existing platforms.
This patch simply promotes the sysdeps/posix implementation to
universal, and removes the Linux-specific implementation, whose
apparent reason for existing was to cut out one function call's worth
of overhead.
Checked on x86_64-linux-gnu, i686-linux-gnu, powerpc64le-linux-gnu,
powerpc64-linux-gnu, powerpc-linux-gnu, and aarch64-linux-gnu.
Reviewed-by: Lukasz Majewski <lukma@denx.de>
ftime is an obsolete variation on gettimeofday, offering only
millisecond time resolution; it was probably a system call in ooold
versions of BSD Unix. For historic reasons, we had three
implementations of it. These are all consolidated into time/ftime.c,
and then the function is deprecated.
For some reason, the implementation of ftime in terms of gettimeofday
was rounding rather than truncating microseconds to milliseconds. In
all the other places where we use a higher-resolution time function to
implement a lower-resolution one, we truncate. ftime is changed to
match, just for tidiness' sake.
Like gettimeofday, ftime tries to report the time zone, and using that
information is always a bug. This patch dummies out the reported
timezone information; the timezone and dstflag fields of the
returned "struct timeb" will always be zero.
Checked on x86_64-linux-gnu, i686-linux-gnu, powerpc64le-linux-gnu,
powerpc64-linux-gnu, and powerpc-linux-gnu.
Co-authored-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Lukasz Majewski <lukma@denx.de>
As for gettimeofday, time will be implemented based on clock_gettime
on all platforms and internal code should use clock_gettime
directly. In addition to removing a layer of indirection, this will
allow us to remove the PLT-bypass gunk for gettimeofday.
The changed code always assumes __clock_gettime (CLOCK_REALTIME)
or __clock_gettime (CLOCK_REALTIME_COARSE) (for Linux case) cannot
fail, using the same rationale for gettimeofday change. And internal
helper was added (time_now).
Checked on x86_64-linux-gnu, i686-linux-gnu, powerpc64le-linux-gnu,
powerpc64-linux-gnu, and powerpc-linux-gnu.
Reviewed-by: Lukasz Majewski <lukma@denx.de>
Change the default implementation of time to call clock_gettime,
to align with new Linux ports that are expected to only implement
__NR_clock_gettime. Arch-specific implementation that either call
the time vDSO or route to gettimeofday vDSO are not removed.
Also for Linux, CLOCK_REALTIME_COARSE is used instead of generic
CLOCK_REALTIME clockid. This takes less CPU time and its behavior
better matches what the current glibc does.
Checked on x86_64-linux-gnu, i686-linux-gnu, powerpc64le-linux-gnu,
powerpc64-linux-gnu, powerpc-linux-gnu, and aarch64-linux-gnu.
Co-authored-by: Zack Weinberg <zackw@panix.com>
Reviewed-by: Lukasz Majewski <lukma@denx.de>
Unconditionally, on all ports, use clock_settime to implement
settimeofday. Remove sysdeps/unix/clock_settime.c, which implemented
clock_settime by calling settimeofday; new OS ports must henceforth
provide a real implementation of clock_settime.
Hurd had a real implementation of settimeofday but not of
clock_settime; this patch converts it into an implementation of
clock_settime. It only supports CLOCK_REALTIME and microsecond
resolution; Hurd/Mach does not appear to have any support for
finer-resolution clocks.
The vestigial "set time zone" feature of settimeofday complicates the
generic settimeofday implementation a little. The only remaining uses
of this feature that aren't just bugs, are using it to inform the
Linux kernel of the offset between the hardware clock and UTC, on
systems where the hardware clock doesn't run in UTC (usually because
of dual-booting with Windows). There currently isn't any other way to
do this. However, the callers that do this call settimeofday with
_only_ the timezone argument non-NULL. Therefore, glibc's new
behavior is: callers of settimeofday must supply one and only one of
the two arguments. If both arguments are non-NULL, or both arguments
are NULL, the call fails and sets errno to EINVAL.
When only the timeval argument is supplied, settimeofday calls
__clock_settime(CLOCK_REALTIME), same as stime.
When only the timezone argument is supplied, settimeofday calls a new
internal function called __settimezone. On Linux, only, this function
will pass the timezone structure to the settimeofday system call. On
all other operating systems, and on Linux architectures that don't
define __NR_settimeofday, __settimezone is a stub that always sets
errno to ENOSYS and returns -1.
The settimeoday syscall is enabled on Linux by the flag
COMPAT_32BIT_TIME, which is an option to either 32-bits ABIs or COMPAT
builds (defined usually by 64-bit kernels that want to support 32-bit
ABIs, such as x86). The idea to future 64-bit time_t only ABIs
is to not provide settimeofday syscall.
The same semantics are implemented for Linux/Alpha's GLIBC_2.0 compat
symbol for settimeofday.
There are no longer any internal callers of __settimeofday, so the
internal prototype is removed.
Checked on x86_64-linux-gnu, i686-linux-gnu, powerpc64le-linux-gnu,
powerpc64-linux-gnu, powerpc-linux-gnu, and aarch64-linux-gnu.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Lukasz Majewski <lukma@denx.de>
Unconditionally, on all ports, use clock_settime to implement stime,
not settimeofday or a direct syscall. Then convert stime into a
compatibility symbol and remove its prototype from time.h.
Checked on x86_64-linux-gnu, i686-linux-gnu, powerpc64le-linux-gnu,
powerpc64-linux-gnu, powerpc-linux-gnu, and aarch64-linux-gnu.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Lukasz Majewski <lukma@denx.de>
The valid_nanoseconds () static inline function has been introduced to
check if nanoseconds value is in the correct range - greater or equal to
zero and less than 1000000000.
The explicit #include <time.h> has been added to files where it was
missing.
The __syscall_slong_t type for ns has been used to avoid issues on x32.
Tested with:
- scripts/build-many-glibcs.py
- make PARALLELMFLAGS="-j12" && make PARALLELMFLAGS="-j12" xcheck on x86_64
Building the test cases in parallel might make tst-strftime2 and
tst-strftime3 fail. Simply re-running the test case (or building
serially) makes the problem go away. This patch adds the necessary
dependency to allow parallel builds in the time subdirectory.
Tested for powerpc64le.
Reviewed-by: Florian Weimer <fweimer@redhat.com>
Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
If we are running on a 32-bit system with a 64-bit time_t we need to
ensure there is padding around the tv_nsec variable. This is requried as
the timespec is #defined to the __timespec64 struct.
* time/bits/types/struct_timespec.h: Add padding for the timespec if
required.
It moves the missing CFLAGS from rt/Makefile to time/Makefile missing
from 7b5af2d8f2 (Finish move of clock_* functions to libc. [BZ #24959]).
Checked on powerpc64le-linux-gnu.
* rt/Makefile (CFLAGS-clock_nanosleep.c): Move to ...
* time/Makefile (CFLAGS-clock_nanosleep.c): ... here.
In glibc 2.17, the functions clock_getcpuclockid, clock_getres,
clock_gettime, clock_nanosleep, and clock_settime were moved from
librt.so to libc.so, leaving compatibility stubs behind. Now that the
dynamic linker no longer insists on finding versioned symbols in the
same library that originally defined them, we do not need the stubs
anymore, and this means we don't need GLIBC_PRIVATE __-prefix aliases
for most of the functions anymore either. (clock_gettime still needs
one.) For ports added before 2.17, libc.so needs to provide two
symbol versions for each, the default at GLIBC_2.17 plus a compat
version matching what librt had.
While I'm at it, move the clock_*.c files and their tests from rt/ to
time/.
It doesn't make sense to remove all the internal uses of time.
It's still a standard ISO C function, and its callers don't need
sub-second resolution and would be unnecessarily complicated if
they had to declare a struct timespec instead of just a time_t.
However, a handful of places were using the vestigial "result"
argument instead of the return value, which is slightly less
efficient and also looks strange. Correct this.
* misc/syslog.c (__vsyslog_internal)
* time/getdate.c (__getdate_r)
* time/tst_wcsftime.c (main):
Use return value of time, not its argument.
* string/strfry.c (strfry)
* sysdeps/mach/sleep.c (__sleep):
Remove unnecessary casts of NULL in calls to time.
Keep these functions compatible with Gnulib while adding
__time64_t support. The basic idea is to move private API
declarations from include/time.h to time/mktime-internal.h, since
the former file cannot easily be shared with Gnulib whereas the
latter can.
Also, do some other minor cleanup while in the neighborhood.
* include/time.h: Include stdbool.h, time/mktime-internal.h.
(__mktime_internal): Move this prototype to time/mktime-internal.h,
since Gnulib needs it.
(__localtime64_r, __gmtime64_r) [__TIMESIZE == 64]:
Move these macros to time/mktime-internal.h, since Gnulib needs them.
(__mktime64, __timegm64) [__TIMESIZE != 64]: New prototypes.
(in_time_t_range): New static function.
* posix/bits/types.h (__time64_t) [__TIMESIZE == 64 && !defined __LIBC]:
Do not define as a macro in this case, so that portable code is
less tempted to use __time64_t.
* time/mktime-internal.h: Rewrite so that it does both glibc
and Gnulib work. Include time.h if not _LIBC.
(mktime_offset_t) [!_LIBC]: Define for gnulib.
(__time64_t, __gmtime64_r, __localtime64_r, __mktime64, __timegm64)
[!_LIBC || __TIMESIZE == 64]: New macros, mostly moved here
from include/time.h.
(__gmtime_r, __localtime_r, __mktime_internal) [!_LIBC]:
New macros, taken from GNulib.
(__mktime_internal): New prototype, moved here from include/time.h.
* time/mktime.c (mktime_min, mktime_max, convert_time)
(ranged_convert, __mktime_internal, __mktime64):
* time/timegm.c (__timegm64):
Use __time64_t, not time_t.
* time/mktime.c: Stop worrying about whether time_t is floating-point.
(__mktime64) [! (_LIBC && __TIMESIZE != 64)]:
Rename from mktime.
(mktime) [_LIBC && __TIMESIZE != 64]: New function.
* time/timegm.c [!_LIBC]: Include libc-config.h, not config.h,
for libc_hidden_def.
Include errno.h.
(__timegm64) [! (_LIBC && __TIMESIZE != 64)]:
Rename from timegm.
(timegm) [_LIBC && __TIMESIZE != 64]: New function.
First cut at publicizing __time64_t
snprintf will only truncate the output if the data its given
is corrupted, but a truncated buffer will not match the
"pristine" data's buffer, which is all we need. So just
disable the warning via the DIAG macros.
The Japanese era name will be changed on May 1, 2019. The Japanese
government made a preliminary announcement on April 1, 2019.
The glibc ja_JP locale must be updated to include the new era name for
strftime's alternative year format support.
Checked on x86_64-linux-gnu.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
ChangeLog:
[BZ #22964]
* localedata/locales/ja_JP (LC_TIME): Add entry for the new Japanese
era.
* time/tst-strftime2.c (dates): Add 2019-04-30 and 2019-05-01.
(mkreftable): Add rules for the new Japanese era and the new dates.
Co-authored-by: Rafal Luzynski <digitalfreak@lingonborough.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
ChangeLog:
[BZ #24293]
* time/Makefile (LOCALES): Add zh_TW.UTF-8, cmn_TW.UTF-8,
hak_TW.UTF-8, nan_TW.UTF-8, and lzh_TW.UTF-8.
* time/tst-strftime2.c (locales): Likewise.
(dates): Add 1910-04-01, 1911-12-31, 1912-01-01, 1913-04-01,
2010-04-01, and 2011-04-01.
(mkreftable): Add rules for the new locales and the new dates.
Express the years as full Gregorian years (e.g., 1988 instead of 88)
and months with natural numbers (1-12 rather than 0-11).
Compare actual dates rather than indexes when selecting the era name.
Declare the local variable era as a string character pointer rather
than an array of chars where the actual string is copied which might
lead to potential buffer overflows in future.
Co-authored-by: Rafal Luzynski <digitalfreak@lingonborough.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
ChangeLog:
* time/tst-strftime2.c (date_t): Explicitly define the type.
(dates): Use natural month and year numbers to express a date.
(is_before): New function to compare dates.
(mkreftable): Minor improvements to simplify maintenance.
(do_test): Reflect the changes in dates array.
Test the transition points between all the currently listed Japanese
era name changes. This includes testing the transition between the
first year date and the second year date. This test will help test
the upcoming Japanese era name change.
Also fixes a fencepost error where the era name isn't properly parsed
by strptime in the last (partial) year of the era.
Example: if an era change happens in Feb 1990, and again in Aug 1995,
that's 5.5 years long, but the 0.5 year wasn't accounted for.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
