Comment 3 for bug 790574

Thanks for your feedback. I searched for an example multiline scheme string and found one in the aging report:
 (cons #f (sprintf
 (_ "Transactions relating to '%s' contain \
more than one currency. This report is not designed to cope with this possibility.") (gncOwnerGetName owner))))

This used to be extracted to the pot file as:
#. src/report/business-reports/aging.scm
#. src/report/business-reports/gnucash/report/aging.scm
#: ../intl-scm/guile-strings.c:624 ../intl-scm/guile-strings.c:1228
#, c-format
msgid "Transactions relating to '%s' contain more than one currency. This report is not designed to cope with this possibility."
msgstr "De boekingen die betrekking hebben op ‘%s’ bevatten meerdere valuta. Dit rapport is niet op die mogelijkheid toegerust."
(I have added an example translation)

After xgettext extraction and merge with an existing translation it becomes:
#: /kobaltnet/janssege/Development/EclipseGnuCash/GnuCash-git/po/../src/report/business-reports/aging.scm:212
msgid ""
"Transactions relating to '%s' contain more than one currency. This report "
"is not designed to cope with this possibility."
msgstr ""
"De boekingen die betrekking hebben op ‘%s’ bevatten meerdere valuta. Dit "
"rapport is niet op die mogelijkheid toegerust."

Note that I didn't edit the translation file manually. msgmerge seems to recognize a string as identical regardless of it being split over multiple lines and adds line breaks in existing translation by itself as well.

So unless I am missing something, it seems to me that xgettext does support multiline extractions now.