Im sure this has already been asked, but its a bit hard to search for.

How do i reset a pattern ?

Lets say i converted a path into a Pattern and applied it to, say, a rectangle, via the Fill Style-Pattern.
Next i rotated and scaled the Patternfill with the Node Tool.
How do i go back to the original size and position ?

Is this possible via the XML Editor ?

Hi.

If you set a solid colour and the original pattern fill after, the transformation is "gone".

Other "workaround" with the xml editor:
in the style attribute there is a part saying "fill:url(#pattern371058)" or something similar. Look up the linked pattern -with the same id- in the defs section. There is a patternTransform field. If you select it, you can delete the given matrix and set no transformation.
However that may not bring you to the expected result. It will remove scaling and translating as well and the pattern handles will relocate.
Tried it with the 1:1 stripes built in pattern, the result is way scaled down.

Thanks !

Your procedure did not work for me.

However i accidentally discovered: when i remove the pattern and re-apply, position and size are reset.