[yocto] bitbake: git and patch problem

[EXTERNAL van Riel Rob (ENTER, BT-CO/ENG1.1)]

I'm experiencing strange (at least to my eyes) behaviour from bitbake. My recipe specifies a git repository as the main SRC_URI, then, in a variant created using an append file adds a patch like this:

SRC_URI_append_mystuff += "file://mystuff.patch"

As expected, this grabs the sources from the git repository, and then applies the patch. Rather unexpectedly to me, and also rather inconveniently, it then adds and commits the changes to the local git clone.

Is this expected behaviour, and if so, is there any way to prevent it?

My environment is based on poky-fido-13.0.1.

Best regards,

Rob van Riel