Why is cd appending dirs like pushd?

Question

I am using zsh in Babun (Cygwin with oh-my-zsh and some extras).

I noticed some odd behavior, it looks like cd is behaving like pushd?

{ ~ }  » mkdir foo
{ ~ }  » pushd foo
~/foo ~
{ foo }  » popd
~

The above is fine and expected, but see the below.

{ ~ }  » cd foo
{ foo }  » dirs
~/foo ~

I tried checking if there was some alias being set somewhere, but I saw no such thing.

{ foo }  » alias | egrep "(cd|pushd)"
-='cd -'
1='cd -'
2='cd -2'
3='cd -3'
4='cd -4'
5='cd -5'
6='cd -6'
7='cd -7'
8='cd -8'
9='cd -9'
grt='cd $(git rev-parse --show-toplevel || echo ".")'
pu=pushd

Why is my cd appending dirs? It's not really a problem, I am more just curious.

Answer 1

I see now. oh-my-zsh does setopt auto_pushd which is described here as:

AUTO_PUSHD (-N)

• Make cd push the old directory onto the directory stack.