Blender Git Loki

Gpencil: Fix for SVG import arc and float errors

Fix for the Arc commands (A/a) to successfully parse the 4th and 5th arguments.
Fix for floats without a specified integer part, like `.123`

File for testing:
{F10042021}

Reviewed By: filedescriptor

Differential Revision: https://developer.blender.org/D11099