https://bugs.kde.org/show_bug.cgi?id=382437
//One cause of the bug is commit at plasma-integration:
author Elvis Angelaccio <elvis.angelaccio@kde.org> 2017-05-23 10:48:24 (GMT)
commit 0dafb9403266d6064074250d44b74dc0db946cfb
/src/platformtheme/kdeplatformfiledialoghelper.cpp
parent 708ff0d0b2905e4c68a9fb22b8a2f439d2f2fb65 (diff)0dafb9403266d6064074250d44b74dc0db946cfb
//Make sure we always set a default mime filter in save mode
KFileWidget::setMimeFilter() documentation says a default mime filter
should be set if the dialog is being open in save mode.
Without a default filter, the dialog uses a custom item (created by
concatenating all the mime type filters) as default. This is not useful
because it means an additional click for the user to select a filter that can
actually be useful.
If the initiallySelectedMimeTypeFilter() is empty, we use the first mime
fIf the initiallySelectedMimeTypeFilter as fallback.() is empty, we use the first mime
filter as fallback.//
Chrome opens kdialog with 2 mime types: application/octet-stream (means any file) and (for example) image/jpeg. But application/octet-stream is associated with *.bin extension. When you choose this mime extention becomes *.bin. That commit does this mime default (it's first).
This patch blocks changing extention to bin for "application/octet-stream" selected.