Import of different content language changes the master content

Description

Steps to reproduce

1. From Site1, export content with many language versions, for example (en (master language),sv, fr).
2. Import content to Site2 (of only one language, like sv). The sv content should be imported and be the master language.
3. Import content to Site2 ( in the fr language) with update the same Id.

Expected:
The fr content should be imported as a language branch.

Actual:
The sv content is modified.

NOTE: To reproduce the issue, import language versions of content without going back to Edit mode.