Incorrect style inheritance in text when converting text to path

Migrated from: https://bugs.launchpad.net/inkscape/+bug/539174

Steps to reproduce:

• open Inkscape
• open demo file: style_inheritance.svg
• Convert the text object to a path.

To recreate from scratch:

• open Inkscape
• make sure that Settings->Text->"Use SVG2 flowed text" is unchecked Edit: also replicated with SVG2 flowed text
• draw a text rectangle and type something ("Hello World")
• Select tool -> Select the text -> set fill to a color
• Text tool -> Select all text -> set fill to black again
• Select a part of the text and make it italic to create a nested flowSpan
• Convert the text object to a path.

What happened?

The second sentence becomes blue.

What should have happened?

The second sentence stays black. The flowRoot has a fill of #3399 (closed), but the flowPara has a fill of #000000. Inside the flowPara is a nested flowspan without a style attribute. Inkscape apparently incorrectly computes the style of the flowspan when converting to path.

Also affects SVG2 flowed text with nested tspans.

Inkscape Version and Operating System:

• Inkscape Version: 1.1-dev (12e2a095, 2020-02-19)
• Operating System: Windows 10
• Operating System version: 10.0.18362

Migration info

reproduced on

• Windows XP, bzr rev 9192
• Inkscape 0.47pre4 r22446 (Oct 15 2009) (Ubuntu version 0.47~pre4-0ubuntu1, as included in karmic 9.10, on x86-64).

More complex example from the Launchpad bug: poster.svg (convert the text below "Methods" to see the italic parts of the text change color)