Copy -and-paste for QDoc does not preserve indentation

When copy&pasting an indented structure from one QDoc file to a different one, the outermost indentation level is reduced to one space.

Something like

\list
    \li first
    \li second
\endlist

becomes

\list
 \li first
 \li second
\endlist

Higher-level indentation is moved to the left by the same amount, so that relative indentation levels remain unchanged.