Comment 5 for bug 1354339

A related problem I think.

1. new (pixels document units)
2. draw three rectangles.
3. select the first one and fill with stripes 1:1
4. change document units to mm.
5. select the 2nd rectangle and fill with stripes 1:1
6. change the document units to in.
7. select the 3rd rectangle and fill with stripes 1:1

Result, the stripe pattern is different in all 3 rectangles. Click on any one
of the rectangles and the fill and stroke dialog will show "stripes 1:1". Try changing
them to other fill patterns and they are all big black blobs (for most patterns) because
in the attached example, after the "in" change the widths and heights are about 1 inch, but
the defs for the patterns are in pixels, and they are mostly bigger than 1.

This is, I believe, another manifestation of a document unit problem. These come about because
on document unit changes all lengths and coordinates are transformed recursively, that is, the actual values are changed ( it isn't that a single transform at the top is changed, doing that doesn't break links to objects in defs), but <defs> isn't similarly modified. So things break, like here, and bugs #1348417 and #1302857.