See the code and comments here:
Fixed in jet-main.
Integrated into 'main-golden', will be available in build *201203230400* on http://bits.netbeans.org/dev/nightly/ (upload may still be in progress)
User: Dusan Balek <email@example.com>
Log: Issue #201130: Pasting a string containing newlines should insert "+" escapes - fixed.
*** Bug 100576 has been marked as a duplicate of this bug. ***
*** Bug 68804 has been marked as a duplicate of this bug. ***