Merge branch 'sb/fix-fetching-moved-submodules'

The code to try seeing if a fetch is necessary in a submodule during a fetch with --recurse-submodules got confused when the path to the submodule was changed in the range of commits in the superproject, sometimes showing "(null)". This has been corrected. * sb/fix-fetching-moved-submodules: t5526: test recursive submodules when fetching moved submodules submodule: fix NULL correctness in renamed broken submodules