For letter which has "print automatically inserted blank pages" set, it is not used during printing.
Steps to Reproduce:
1. Open empty writer document
2. Ensure that "print automatically insterted blank pages" setting is off (Tools -> Options -> LibreOffice Writer -> Print -> Print automatically inserted blank pages. Disable it, if it is on.
3. Open letter.odt file
4. Ensure that "Print automatically inserted blank pages" is on (see p.2).
5. Start mail merge wizard (Tools -> Mail Merge wizard…
6. "Use current document", click "Next"
7. "Letter", click "Next"
8. Select as a datasource adressen5.ods and match fields
9. After wizard finish select "Print merged documents" on newly appeared toolbar and print document (I use PDF printer).
Printed document contains 5 pages, one page per letter (see result.pdf).
Printed document contains 9 pages, one page per letter and 4 blank pages in between due to "print automatically inserted blank pages" is set (see expected_result.pdf).
User Profile Reset: No
User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:60.0) Gecko/20100101 Firefox/60.0
Created attachment 142154 [details]
Current result (PDF printer)
Created attachment 142155 [details]
Expected result (PDF printer)
Created attachment 142156 [details]
Created attachment 142157 [details]
Vasily Melenchuk committed a patch related to this issue.
It has been pushed to "master":
tdf#117664: mailmerge: copy printer settings to new mailmerge document
It will be available in 6.1.0.
The patch should be included in the daily builds available at
http://dev-builds.libreoffice.org/daily/ in the next 24-48 hours. More
information about daily builds can be found at:
Affected users are encouraged to test the fix and report feedback.