Dear Maintainer,

When a document type is not defined setting tab-width in the drop-down configuration behaves as expected, but when the file is saved and identified as a document type or when a document type is specified manually, a pre-defined tab-width is used and the user selected tab-width is ignored.

Example: with Javascript selected as language tab-width is 4 spaces, regradless of whether the user selects "2" or "8".