Hello, I don't know is it bug or future, could you explain please.

Try to do th following:
1) copy to clipboard any text (for example "test")
2) paste (Ctrl+V) it;
3) cursor is at the and of the word (symbol "|" - is cursor);

4) Try to press SHIFT and click left mouse button at the beginning of the pasted text. So your cursor should be here:

So it looks like cursor was left at the beginning of pasted text...
5) But text is not selected
6) if you try to use keyboard left cursor key - text is selected...

Would you be so kind to tell:
is that a future or (annoying for me) a bug?

Thank you very much!

It's a minor problem, not an intended behaviour. Will be fixed in build 4630.