Fix parsing of or groups in build-deps with ignored packages

If the last alternative(s) of an Or group is ignored, because it does
not match an architecture list, we would end up keeping the or flag,
effectively making the next AND an OR.

For example, when parsing (on amd64):

    debhelper (>= 9), libnacl-dev [amd64] | libnacl-dev [i386]
 => debhelper (>= 9), libnacl-dev |

Which can cause python-apt to crash.

Even worse:

     debhelper (>= 9), libnacl-dev [amd64] | libnacl-dev [i386], foobar
  => debhelper (>= 9), libnacl-dev [amd64] | foobar

By setting the previous alternatives Or flag to the current Or flag
if the current alternative is ignored, we solve the issue.

LP: #1694697
(cherry picked from commit 7ddf958e370d13f93edc6923bee289b2f6444b41)
(cherry picked from commit 423ba4a958b9da02926e586bf59995817cafc32a)

0 files changed, 0 insertions, 0 deletions