Don't try to determine interactivity if ui() called with interactive=False. WSGI applications are not supposed to refer to sys.stdin. In ed6df6b1c29a, hgweb and hgwebdir were fixed to pass interactive=False to their ui()'s, but sys.stdin.isatty() was still called by the ui objects. This change makes sure only the ui.fixconfig() method will call ui.isatty() (by making the ui._readline() method, which is currently only called from ui.prompt(), private). ui.fixconfig() is changed to let config files override the initial interactivity setting, but not check isatty() if interactive=False was specified in the creation of the ui.

#!/bin/sh

echo "[extensions]" >> $HGRCPATH
echo "mq=" >> $HGRCPATH

hg init a
cd a
echo a > a
hg ci -Ama

hg qnew a.patch
echo a >> a
hg qrefresh

hg qnew b.patch
echo b > b
hg add b
hg qrefresh

hg qnew c.patch
echo c > c
hg add c
hg qrefresh

hg qgoto a.patch
hg qgoto c.patch
hg qgoto b.patch