Left: tab size is correct (8 spaces) when viewing code
Right: tab size is wrong (6 spaces) when viewing diff
I think this is because of data-code-marker (the column to show + and - signs), which is 2 spaces wide. A possible solution may be to wrap the actual code inside a <span class="d-inline-block">. (Sourcegraph seems to use this and it displays tab size correctly in diff.)
