It is otherwise impossible to determine which test failed sanitizer/valgrind
check. test/functional/helpers.lua module return was changed so that tests which
do not provide after_each function to get new check will automatically fail.
Problem: gettabvar() doesn't work after Vim start. (Szymon Wrozynski)
Solution: Handle first window in tab still being NULL. (Christian Brabandt)
7e47d1ac6a