I think the lines https://github.com/gentoo/gentoo/blob/master/app-office/texstudio/files/texstudio-2.10.6-desktop.patch#L14-L15 text/x-tex -> text/X-tex are obsolete (or even wrong?), because I found on my gentoo system text/x-tex $ cat /etc/mime.types | grep "text/.-tex" text/x-tex Please correct me, if I'm wrong.
found the definition now. It is "text/x-tex" https://cgit.freedesktop.org/xdg/shared-mime-info/tree/freedesktop.org.xml.in#n5942
commit 5ab76a7c58637868046230813fbc28571441afa3 Author: Manuel Rüger <mrueg@gentoo.org> Date: Thu Aug 25 17:43:36 2016 +0200 app-office/texstudio: Version bump to 2.11.0 Gentoo-Bug: #581520 Gentoo-Bug: #586854 Gentoo-Bug: #584888 Gentoo-Bug: #590702 Package-Manager: portage-2.3.0 Should be fixed in here, please test if it works.