The issue I have is here:
https://stackoverflow.com/questions/23765413/scintilla-fold-margin-icons
I think this might be a bug rather than a coding issue as Ive now tried changing SC_MARKNUM_FOLDEROPEN and SC_MARKNUM_FOLDER to all the available images but on the fold point the artifacts appear, they only show on the fold level.
There doesn't appear to be any indication of platform and GUI toolkit. There have been some recent image persistence issues on GTK+ 3.x.
Sorry, it's the latest SciLexer.DLL included with SciTE and it's running on Windows (Windows 8 and XP).
Appears as though there is another marker with the default black circle appearance behind the fold marker.
You should also set up all the SC_MARKNUM_FOLDER*.
Hi Neil, thanks for that, set the three remaining SC_MARKNUM_FOLDER's and the issue is fixed.