Fix language load after including keywords from this language in another file
When keywords are included from "X" language, the syntax highlighting of the "X" language will not be loaded:
- The "IncludeRules" rule, from the "X" language, doesn't work.
- It isn't possible to open files of the "X" language while the text editor is open.
Also, this bug can be noticed when opening a SCSS file and then a CSS file; the CSS file is not loaded, since SCSS includes CSS keywords.
This happens, because when, in DefinitionData, if keywordIsLoaded is true, the loadHighlighting(...) method is returned and doesn't read the content of the <highlighting> tag.
Reviewers: Framework: Syntax Highlighting, cullmann, dhaumann, vkrause, jpoelen
Reviewed By: Framework: Syntax Highlighting, cullmann
Subscribers: kwrite-devel, kde-frameworks-devel
Differential Revision: https://phabricator.kde.org/D17085