Unexpected behaviour in marker fill -- 1.1-dev (7802ed9, 2020-09-04)

Triaging issues mentioned in #3525 (closed)

Summary:

Open the attached .svg file created in (7802ed9, 2020-09-04) in the same version and then in <= (48d18c81, 2020-07-08)

N.B.: the arrowhead marker renders before the end of the stroke in Chromium and Safari and doesn't render at all in Firefox. Apparently...

• Chromium/Safari (WebKit) handles fill:context-stroke but not stroke:context-stroke. If you change the stroke to black, the rendering should match Inkscape.
• fill:context-stroke (SVG2) is not used by Firefox. Switching it to fill:black renders the marker in the same place as in Chromium/Safari.

From the Inkscape manual...

Two problems exist with Markers. The first is that Markers do not take the color of the stroke.

In fact (48d18c81, 2020-07-08) and (1.0+r73+1) take color from the fill (note the above screenshot), but (7802ed9, 2020-09-04) does take its color from the stroke, as illustrated in the svg file. Is this supposed to be considered a fix? Neither version's marker reflect what is written in the manual.

N.B.: In (48d18c81, 2020-07-08) and (1.0+r73+1), the file opens with a black arrowhead marker but when selected immediately fills with fill color.

Additional Information/Comments:

Our esteemed colleague @nathanal wrote...

Replicate behaviour. I think there are some issues about marker color but what happens in 1.0/old 1.1-dev is expected, based on default preferences (Preferences > Behaviour > Markers).

We probably want to change the behaviour moving forward after that MR (and it looks like it has been changed). I haven't looked into how it has changed though. (UX and/or bug?)

I have always used the default preferences regarding the markers and tested with the defaults:

• Markers
  • Color stock markers the same color as object
  • Color custom markers the same color as object
  • Update marker color when object color changes

Version Info:

- Inkscape Version(s):
  - 1.1-dev (7802ed9, 2020-09-04), macOS 10.13.6 (17G12034)
  - 1.1.0-dev (48d18c81, 2020-07-08), macOS 10.13.6 (17G12034)
  - 1.1-dev (156e408be7, 2020-09-02), snap package, Ubuntu 18.04.4 LTS
  - 1.0 (1.0+r73+1), Ubuntu 18.04.4 LTS