[BUG] git pull with pull.rebase and rebase.autoStash is not working anymore in 2.16

Looks like regression in 2.16. Worked fine before update. Seems like git stash is not always working. Any ideas?

$ git --version git version 2.16.0.windows.2

$ git config pull.rebase true

$ git config rebase.autoStash true

$ git status
On branch develop
Your branch is behind 'origin/develop' by 3 commits, and can be fast-forwarded.
  (use "git pull" to update your local branch)

Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)
  (use "git checkout -- <file>..." to discard changes in working directory)

        modified:   source_work/xxxxx.cpp

no changes added to commit (use "git add" and/or "git commit -a")

$ git pull Created autostash: 7ddcdf2ba HEAD is now at ba14a4c3f some commit Cannot rebase: You have unstaged changes. Please commit or stash them.

$ git status
On branch develop
Your branch is behind 'origin/develop' by 3 commits, and can be fast-forwarded.
  (use "git pull" to update your local branch)

You are currently rebasing.
  (all conflicts fixed: run "git rebase --continue")

Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)
  (use "git checkout -- <file>..." to discard changes in working directory)

        modified:   source_work/xxxxx.cpp

no changes added to commit (use "git add" and/or "git commit -a")

$ git rebase --abort Applied autostash.

$ git stash Saved working directory and index state WIP on develop: ba14a4c3f some commit

$ git status
On branch develop
Your branch is behind 'origin/develop' by 3 commits, and can be fast-forwarded.
  (use "git pull" to update your local branch)

Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)
  (use "git checkout -- <file>..." to discard changes in working directory)

        modified:   source_work/xxxxx.cpp

no changes added to commit (use "git add" and/or "git commit -a")

$ git stash Saved working directory and index state WIP on develop: ba14a4c3f some commit

$ git status
On branch develop
Your branch is behind 'origin/develop' by 3 commits, and can be fast-forwarded.
  (use "git pull" to update your local branch)

nothing to commit, working tree clean