CI: work around Gitlab Cobertura parsing quirk

This should not be necessary, but my testing with fd.o Gitlab 13.9.1
shows this is needed. Otherwise the coverage markings will not appear in
a MR diff view.

Apparently Gitlab has some problem with 'filename' attribute containing
"../" in Cobertura XML files, even when that does result in a correct
path. Or maybe the problem is is with the <source> path referring to the
build dir which from Gitlab perspective does not exist in the project,
even though builddir/../ is a good path.

This sed hack removes the "../" part and the last element in the
<source> path correspondingly.

See https://gitlab.freedesktop.org/wayland/weston/-/merge_requests/567
for my testing.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>

.gitlab-ci.yml

@@ -109,6 +109,7 @@ build-native-meson-default-options:
   after_script:
   - ninja -C build-* coverage-html
   - ninja -C build-* coverage-xml
+  - sed -i -e 's/\/build-weston-build-native-meson-default-options//' -e 's/\"..\//\"/' build-*/meson-logs/coverage.xml
   artifacts:
     reports:
       cobertura: build-*/meson-logs/coverage.xml