Fix touch timezone calculation

[ctsk]

The timezone offset calculation didn't take into account that some locales change their UTC offset throughout the year (like due to daylight savings time). This change fixes.

Fixes #4236

[sylvestre]

Could you please add a test to make sure it doesn't regress?

[jfinkels]

looks like there were some test failures in the CI; I've restarted it and copied the failures I saw here:

failures:

error: test failed, to rerun pass '-p coreutils --test tests'
---- test_touch::test_touch_tz_crosses_dst stdout ----
current_directory_resolved: 
run: /home/runner/work/coreutils/coreutils/target/debug/coreutils touch -t 202301010000 -a test_touch_tz_crosses_dst_file
thread 'test_touch::test_touch_tz_crosses_dst' panicked at 'assertion failed: t1 == atime_cet.seconds() + 60 * 60', tests/by-util/test_touch.rs:863:5
stack backtrace:
   0: rust_begin_unwind
             at /rustc/7737e0b5c4103216d6fd8cf941b7ab9bdbaace7c/library/std/src/panicking.rs:584:5
   1: core::panicking::panic_fmt
             at /rustc/7737e0b5c4103216d6fd8cf941b7ab9bdbaace7c/library/core/src/panicking.rs:143:14
   2: core::panicking::panic
             at /rustc/7737e0b5c4103216d6fd8cf941b7ab9bdbaace7c/library/core/src/panicking.rs:48:5
   3: tests::test_touch::test_touch_tz_crosses_dst
             at ./tests/by-util/test_touch.rs:863:5
   4: tests::test_touch::test_touch_tz_crosses_dst::{{closure}}
             at ./tests/by-util/test_touch.rs:850:1
   5: core::ops::function::FnOnce::call_once
             at /rustc/7737e0b5c4103216d6fd8cf941b7ab9bdbaace7c/library/core/src/ops/function.rs:227:5
   6: core::ops::function::FnOnce::call_once
             at /rustc/7737e0b5c4103216d6fd8cf941b7ab9bdbaace7c/library/core/src/ops/function.rs:227:5
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

---- test_who::test_boot stdout ----
current_directory_resolved: 
run: who --version
uutils-tests-info: version for the reference coreutil 'who' is higher than expected; expected: 8.3, found: 8.32
run: who -b
run: /home/runner/work/coreutils/coreutils/target/debug/coreutils who -b
thread 'test_who::test_boot' panicked at 'assertion failed: `(left == right)`

Diff < left / right > :
<         system boot  Jan 31 14:34
>         system boot  Jan 31 15:34
 

', tests/by-util/test_who.rs:32:39
stack backtrace:
   0: rust_begin_unwind
             at /rustc/7737e0b5c4103216d6fd8cf941b7ab9bdbaace7c/library/std/src/panicking.rs:584:5
   1: core::panicking::panic_fmt
             at /rustc/7737e0b5c4103216d6fd8cf941b7ab9bdbaace7c/library/core/src/panicking.rs:143:14
   2: tests::common::util::CmdResult::stdout_is
             at ./tests/common/util.rs:449:9
   3: tests::test_who::test_boot
             at ./tests/by-util/test_who.rs:32:9
   4: tests::test_who::test_boot::{{closure}}
             at ./tests/by-util/test_who.rs:28:1
   5: core::ops::function::FnOnce::call_once
             at /rustc/7737e0b5c4103216d6fd8cf941b7ab9bdbaace7c/library/core/src/ops/function.rs:227:5
   6: core::ops::function::FnOnce::call_once
             at /rustc/7737e0b5c4103216d6fd8cf941b7ab9bdbaace7c/library/core/src/ops/function.rs:227:5
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

---- test_who::test_login stdout ----
current_directory_resolved: 
run: who --version
uutils-tests-info: version for the reference coreutil 'who' is higher than expected; expected: 8.3, found: 8.32
run: who -l
run: /home/runner/work/coreutils/coreutils/target/debug/coreutils who -l
thread 'test_who::test_login' panicked at 'assertion failed: `(left == right)`

Diff < left / right > :
<LOGIN    ttyS0        Jan 31 14:34               717 id=tyS0
<LOGIN    tty1         Jan 31 14:34               748 id=tty1
>LOGIN    ttyS0        Jan 31 15:34               717 id=tyS0
>LOGIN    tty1         Jan 31 15:34               748 id=tty1
 

', tests/by-util/test_who.rs:72:39
stack backtrace:
   0: rust_begin_unwind
             at /rustc/7737e0b5c4103216d6fd8cf941b7ab9bdbaace7c/library/std/src/panicking.rs:584:5
   1: core::panicking::panic_fmt
             at /rustc/7737e0b5c4103216d6fd8cf941b7ab9bdbaace7c/library/core/src/panicking.rs:143:14
   2: tests::common::util::CmdResult::stdout_is
             at ./tests/common/util.rs:449:9
   3: tests::test_who::test_login
             at ./tests/by-util/test_who.rs:72:9
   4: tests::test_who::test_login::{{closure}}
             at ./tests/by-util/test_who.rs:68:1
   5: core::ops::function::FnOnce::call_once
             at /rustc/7737e0b5c4103216d6fd8cf941b7ab9bdbaace7c/library/core/src/ops/function.rs:227:5
   6: core::ops::function::FnOnce::call_once
             at /rustc/7737e0b5c4103216d6fd8cf941b7ab9bdbaace7c/library/core/src/ops/function.rs:227:5
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

---- test_who::test_runlevel stdout ----
current_directory_resolved: 
run: who --version
uutils-tests-info: version for the reference coreutil 'who' is higher than expected; expected: 8.3, found: 8.32
run: who -r
run: /home/runner/work/coreutils/coreutils/target/debug/coreutils who -r
thread 'test_who::test_runlevel' panicked at 'assertion failed: `(left == right)`

Diff < left / right > :
<         run-level 5  Jan 31 14:34
>         run-level 5  Jan 31 15:34
 

', tests/by-util/test_who.rs:100:39
stack backtrace:
   0: rust_begin_unwind
             at /rustc/7737e0b5c4103216d6fd8cf941b7ab9bdbaace7c/library/std/src/panicking.rs:584:5
   1: core::panicking::panic_fmt
             at /rustc/7737e0b5c4103216d6fd8cf941b7ab9bdbaace7c/library/core/src/panicking.rs:143:14
   2: tests::common::util::CmdResult::stdout_is
             at ./tests/common/util.rs:449:9
   3: tests::test_who::test_runlevel
             at ./tests/by-util/test_who.rs:100:9
   4: tests::test_who::test_runlevel::{{closure}}
             at ./tests/by-util/test_who.rs:96:1
   5: core::ops::function::FnOnce::call_once
             at /rustc/7737e0b5c4103216d6fd8cf941b7ab9bdbaace7c/library/core/src/ops/function.rs:227:5
   6: core::ops::function::FnOnce::call_once
             at /rustc/7737e0b5c4103216d6fd8cf941b7ab9bdbaace7c/library/core/src/ops/function.rs:227:5
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.


failures:
    test_touch::test_touch_tz_crosses_dst
    test_who::test_boot
    test_who::test_login
    test_who::test_runlevel

test result: FAILED. 2484 passed; 4 failed; 39 ignored; 0 measured; 0 filtered out; finished in 150.67s

[ctsk]

Hmm... Perhaps the setenv break subsequent tests?

[tertsdiepraam]

We should probably add some function in the test utils that sets an environment variable for the subcommand to make this easier without messing up the env variables.

[github-actions[bot]]

GNU testsuite comparison:

Congrats! The gnu test tests/tail-2/inotify-dir-recreate is no longer failing!

[sylvestre]

@ctsk i noticed that you have closed this PR and https://github.com/uutils/coreutils/pull/4316#event-9068743633 you aren't interested in finishing them? thanks