Spell checking bug when moving cursor in mail composer (confirmed in HTML & Plain Text modes)
I've enabled Finnish spell checking via enchant/enchant-voikko + libvoikko libraries. The spell checking is working correctly when I'm typing new text (it marks mistyped words with the dotted red line and leaves correctly typed words without it) but after I've typed one sentence and then I move cursor backwards it starts to mark all words as mistyped for some reason.
I've verified this bug in multiple Evolution versions: git (2018-10-27), 3.30, 3.26, 3.24 & 3.22 (at least). I also tried to compile the Evolution against enchant2 library but the bug remains. And at the same time I'm unable to reproduce this in gtkhtml-editor-test or in AbiWord (they both are using the same spell checking method as Evolution: Voikko via enchant library).
Here are some screenshots if they help to understand how to reproduce the bug:
I've written Finnish text which is typed correctly:
Then I moved the cursor to left using left arrow key, Evolution starts to mark all words as mistyped:
You can try to reproduce this by installing libvoikko, enchant-voikko packages (in Fedora/CentOS) and enable Finnish spell checking from Evolution's settings and type that sample text and move the cursor then.
I don't believe this is a bug in Voikko (libvoikko/enchant-voikko) because the spell checking is working properly in AbiWord, gtkhtml-editor-test and in LibreOffice.