[ruby-core:99278] [Ruby master Bug#17042] Times with timezones return incorrect week numbers

[gamelinks007@gmail.com]

Issue #17042 has been updated by S_H_ (Shun Hiraoka).


This code resolve this behaviour.

```c
static VALUE
time_strftime(VALUE time, VALUE format)
{
    struct time_object *tobj;
    const char *fmt;
    long len;
    rb_encoding *enc;
    VALUE tmp;

    GetTimeval(time, tobj); 
    if (tobj->vtm.yday == 0) {
        VALUE zone = tobj->vtm.zone;
        if (!NIL_P(zone)) zone_localtime(zone, time);
    }
    MAKE_TM(time, tobj);
    StringValue(format);
    if (!rb_enc_str_asciicompat_p(format)) {
	rb_raise(rb_eArgError, "format should have ASCII compatible encoding");
    }
    tmp = rb_str_tmp_frozen_acquire(format);
    fmt = RSTRING_PTR(tmp);
    len = RSTRING_LEN(tmp);
    enc = rb_enc_get(format);
    if (len == 0) {
	rb_warning("strftime called with empty format string");
	return rb_enc_str_new(0, 0, enc);
    }
    else {
        VALUE str = rb_strftime_alloc(fmt, len, enc, time, &tobj->vtm, tobj->timew,
				      TZMODE_UTC_P(tobj));
	rb_str_tmp_frozen_release(format, tmp);
	if (!str) rb_raise(rb_eArgError, "invalid format: %"PRIsVALUE, format);
	return str;
    }
}
```

`tobj->vtm.yday`is seems to be 0.

So, these code resolve.

```c
    if (tobj->vtm.yday == 0) {
        VALUE zone = tobj->vtm.zone;
        if (!NIL_P(zone)) zone_localtime(zone, time);
    }
```


----------------------------------------
Bug #17042: Times with timezones return incorrect week numbers
https://bugs.ruby-lang.org/issues/17042#change-86666

* Author: timcraft (Tim Craft)
* Status: Open
* Priority: Normal
* ruby -v: ruby 2.8.0dev (2020-07-15 master 79d06483a8)
* Backport: 2.5: UNKNOWN, 2.6: UNKNOWN, 2.7: UNKNOWN
----------------------------------------
Times with timezones return incorrect week numbers from strftime. For example:

    $ irb -r tzinfo
    irb(main):001:0> Time.utc(2020, 7, 22, 12, 0, 0).strftime('%U %V %W')
    => "29 30 29"
    irb(main):002:0> Time.new(2020, 7, 22, 12, 0, 0, TZInfo::Timezone.get('America/New_York')).strftime('%U %V %W')
    => "00 00 00"

Follow up to #17024



-- 
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