atlas_add_test: Fix return code if post.sh is not available
This fixes a bug introduced with !607 (merged). In case the post.sh
script is
not available, the unit test wrapper was returning 0 exit code even if
the test failed. This would only affect projects that do not build
AtlasTest/TestTools
.
The fix is a hack on top of a hack. It's really not nice that we are hardcoding post.sh
in our cmake code to begin with. We should come up with something better for this. But until then, this fix should probably be included rather sooner than later in a new version of atlasexternals.