Using git 2.10.1, I recently lost the contents of an entire directory by running a "git stash" command. I don't know if this known behavior, but it seems pretty dangerous. To trigger the bug, all you have to do is check out a repository containing a symlink, delete the symlink, and then create a directory with files at the path where the deleted symlink was. After this, running "git stash" will recursively delete the directory, leaving no way to recover the data.
Here are minimal steps to reproduce:
mkdir test-repo cd test-repo git init ln -s location symlink git add symlink git commit -m'add symlink' rm symlink mkdir symlink echo important-data > symlink/important-data git stash # recursively deletes entire contents of "symlink" directory