Comment 15 for bug 172137

Jabiertxof wrote 7 hours ago:
> Could you try with fix for bug #1621234 Use one of the patches
> "fix-bug-1621234.v8.xxxxxxx". For the scale be sure you have in
> select tool selected scale stroke width.

Done, as well as with v9 and v10.

The earlier described “flaw” with regard to 'Pattern Along Path' LPE is still present, and also exposed when scaling a just drawn path (with shape 'Ellipse') with 'stroke scaling' turned on:

Unless the Path Effects dialog was opened at least once in the current session (i.e. not restored from last session - that would be equal to opening it in the current session), then any scaling applied to the path with the select tool is not recorded in the path effect definition (SVG source) as value of the 'prop_scale' attribute. The current value though seems to be held somehow in memory and is used to generated the output on-canvas during the current session.

Steps to reproduce:
(please test with new prefs, and in a session with a new doc based on the default template):
1) launch inkscape 0.92.x patched with latest
2) zoom to 100% ('1')
3) switch to the bezier tool ('B')
4) select shape 'Ellipse'
5) draw a path
   (e.g. a curve with cusp start, smooth middle and cusp end node)
6) switch to the select tool ('S')
   Verfiy that stroke scaling is ON (default with new prefs)
7) scale the path uniformly by dragging the upper right transformation
   handle with Ctrl pressed

--> the width of the pattern scales up (or down) as expected.

8) Variants to expose the 'flaw':

8a) duplicate the path and move the duplicate aside
   --> the duplicate reverts to prior pattern width

8b) keep path selected, open the XML Editor
   select the path effect definition in the prefs
   inspect the value of 'prop_scale' attribute (unchanged initial '1')
   open the Path Effects dialog (Shift+Ctrl+&)
   check the 'prop_scale' value again:
   --> now its value has been updated
   (AFAICT corresponds to the path rendered on-canvas)
   further scaling of the path will update the prop_scale value

8c) save and reopen cycles as described earlier

In my understanding, it should not be required to have the 'Path Effects' dialog open in order to have the scaling (the width of the pattern) actually updated to the PaP path effect definition (users do not necessarily need that dialog when working with pencil/bezier shapes).

Slight variations are additionally exposed when copy&pasting the path into a new document (based on the same default template i.e. same document scale) and duplicating the copy afterwards, but that propably needs tracking in a separate report.