Confirmed against git master from today.

The docs say:
>The image formats (PNG, JPEG, and TIFF) generate one file per page with the page number and file type appended to (except when -singlefile is used).

However, this is not the case. The code doesn't test for -singlefile before appending the .png/.jpg/.tif extension.

I would argue this is an issue in the code, and not the docs, but would not object too much if just the docs changed, to preserve backwards compatibility.