Adapted behaviour of ui.username() to documentation and mention it explicitly: Searched in this order: $HGUSER, [ui] section of hgrcs, $EMAIL and stop searching if one of these is set. Abort if found username is an empty string to force specifying the commit user elsewhere, e.g. with line option or repo hgrc. If not found, use $LOGNAME or $USERNAME +"@full.hostname".

Improved ui.edit(): - Use descriptive name for temporary file: hg-editor-*.txt - Don't import tempfile in the method, but use demandload() - Remove tempfile file even if editor aborts.

Pass correct username as $HGUSER to hgeditor if "commit -u" is used. And only use the new util.system parameter to set the environment.