[Help-bash] Wrong result for assign subarray to itself?

[Qu Wenruo]

Hi all,

A strange behavior happens like the following:
---
$ words=('word1' 'word2' 'word3')
$ echo address@hidden
word1 word2 word3            # OK
$ address@hidden:1}
$ echo address@hidden
word2 word3 word2 word3  # What happens here??!!
# Shouldn't the result be ('word2' 'word3') ??
---

Any clue why this happens?

BTW, if using any variant, nothing strange will happen.
---
$ words=('word1' 'word2' 'word3')
$ echo address@hidden
word1 word2 word3            # OK
$ address@hidden:1}
$ echo address@hidden
word2 word3                        # Also OK
---

Thanks,
Qu