Dear Debian Maintainer, https://anonscm.debian.org/hg/xine-lib/xine-lib-1.2/rev/e72410d807a3 seems to fix this bug, but recreation of src/video_out/Makefile.in is needed to get it working (btw. 1.2.7 is out since two months but I guess out of scope for Stretch).
Kind regards Harald Jenny