When I execute the follow set of commands, the `git diff-tree` command
will go on to consume all 30G of ram and then 30G of swap on a system
running Ubuntu 18.04.
git clone git@xxxxxxxxxx:GemTalk/Rowan.git
cd Rowan
git checkout c70f69b50dc90c0a6207a5aa36705b71b59b92b3
git diff-tree -r -p --textconv --submodule -C --cc --no-commit-id -U3
--root c70f69b50dc90c0a6207a5aa36705b71b59b92b3
I'm running git 2.26.2 (built from source). The git command line was
generated by gitk. It originally showed up in 2.17.1, but reproduced in
the latest version of git.
Clicking nearby commits (ccffec29f977f9324e8120bf550c745189e76f70 and
8b08cec96bbb74b54046abbdb49a5bbd2f82fc3b finish almost immediately, so
there seems to be something special about that particular commit.
Dale
