fix: no panic if i.reader.Next() returns an empty result

[akvlad]

Proposed Changes

fix for bug if reader.Next returns an empty result.
Now it results in panic:

panic: runtime error: index out of range [0] with length 0

goroutine 424 [running]:
github.com/apache/arrow/go/v12/arrow/array.(*String).Value(...)
	/go/pkg/mod/github.com/apache/arrow/go/v12@v12.0.0/arrow/array/string.go:54
github.com/InfluxCommunity/influxdb3-go/influx.getArrowValue({0x18e4ed0, 0xc000e44aa0}, 0x0)
	/go/pkg/mod/github.com/!influx!community/influxdb3-go@v0.1.0/influx/query_iterator.go:139 +0x1085
github.com/InfluxCommunity/influxdb3-go/influx.(*QueryIterator).Next(0xc000aa62c0)
	/go/pkg/mod/github.com/!influx!community/influxdb3-go@v0.1.0/influx/query_iterator.go:62 +0x205

Checklist

• CHANGELOG.md updated
• Rebased/mergeable
• A test has been added if appropriate
• Tests pass
• Commit messages are conventional
• Sign CLA (if not already signed)

[bednar]

Hi @akvlad,

Thank you for your PR! 👍

Could you please add a simple test case for your changes? Once that's done, we'll be ready to merge your PR. We appreciate your contribution!

Regards

[akvlad]

This bug was reproduced when I had sent a request over about 200G of data with 5 cores.

I'll think about the way of testing it.

[akvlad]

Added a unit test.
And optimized the fix to one line. :)

[bednar]

@akvlad thanks again for your PR 👍

LGTM 🚀