Use `git rev-parse commit:submodule_path` instead of
`git ls-tree commit submodule_path | awk "{print $3}"`.
git submodule foreach '
# In submodule "$name"
- prev_commit=`(git -C "$toplevel" ls-tree "$from_commit" "$sm_path" | awk "{print \\$3}")`
- curr_commit=`(git -C "$toplevel" ls-tree "$to_commit" "$sm_path" | awk "{print \\$3}")`
+ prev_commit=`(git -C "$toplevel" rev-parse "$from_commit":"$sm_path")`
+ curr_commit=`(git -C "$toplevel" rev-parse "$to_commit":"$sm_path")`
"$prog_dir/$prog_name" $prev_commit $curr_commit
'