In Advanced Tutorial, undoing a move of a "linked offset" unlinks it

On reproductible mean to destroy 'linked offset' object by bug:

In the same tutorial: (after launching inkscape)
*change the stroke size of the red object (the source of the
links)
* move the red object
the two 'linked offset' objects are destroyed.

In current SVN if I create a path and do a linked offset, it does not have this issue. It appears to be a problem with the tutorial file.

still confirmed with 'tutorial-advanced.svg' of revision 22271:

1) move linked offset (black stroke, no fill), crtl-z, node edit inner path (red stroke, no fill) -> black linked offset no longer linked
2) 'destroyed' linked offsets: they are not destroyed but displaced (use 'zoom all' and (shift) <tab> to locate them ;-)

Offset paths have these attributes set:
xlink:href="#advanced-f11-fr.svgpath1987"
inkscape:href="#path1987"

But path1987 doesn't exists elsewhere in the document.

If you use the same value for both attributes (xlink:href="#advanced-f11-fr.svgpath1987",
inkscape:href="#advanced-f11-fr.svgpath1987"), moving a linked offset doesn't break the link anymore.

More tests later on my dev computer.

Made some changes in the xsl file so that it gives inkscape:href the same value as xlink:href.
It corrects the undo bug, but not the displace one (which is not xslt related, I think)...
Partial fix committed in revision 22358.

Thank you for all your efforts to fix the tutorials! Will confirm after my next svn update ;-)

…or rather after the tutorials have been rebuilt.

Tutorials rebuilt (and SVG committed) in revision 22362.

> It corrects the undo bug
Confirmed with Inkscape r22362 on OS X 10.5.8
> but not the displace one (which is not xslt related, I think)...
bug or the transform attributes of the linked offsets are off? If I select the three objects (original and 2 offsets), copy them and 'paste in place' in a new document - their position relative to each other has changed. Don't know if this helps though…

Still investigating this old bug...

Another finding: when the original shape moves, the path and transform attributes are merged and the moved shape no longer have a transform attribute. Thus, if the offset position is calculated on the base of the original path...
And the original path uses absolute points (M115.81,73.567c...) which are changed into relative points (m 121.20293,3337.1639 c) when moved. Maybe something changed in the way Inkscape handles the path points (but I'm too new to tell...).
I'm going to change the original SVG subfile (which contains the 3 shapes only) in order to use relative path directly.

I can reproduce the bug outside the tutorial:
1. Create a new document.
2. Draw a shape.
3. Add a linked offset.
4. With the XML editor, add a transform attribute with translate(100,100) as value to the shape and the offset.
5. Move the original shape.

The new path is now merged with the transform attribute, but the offset uses the new path as its base path, and still adds the transfom values.

Inkscape prevents this bug from happening when the shape is created with its UI by merging the original path and the translate value before creating the offset (and thus no transformation is added to the offset). But when the SVG is created manually or generated by the tutorial generator, Inkscape doesn't detect the issue.

Workaround for the tutorial: create a group with the 3 objects and apply the translation to this group instead of each object separately.

Probably close to Bug #239430 (linked offset ungroup issue), which also deals with transform attribute.

Workaround committed in SVN rev 22700. The tutorials will be committed in bzr later.

The only drawback is that you now have to select the objects inside a group.
The remaining bug is not due to the tutorial, but affects offsets in general, thus I close this report.
Don't hesitate to comment if you have a better workaround.