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

hg init

echo % should fail
hg add .hg/00changelog.i

mkdir a
echo a > a/a
hg ci -Ama
ln -s a b
echo b > a/b

echo % should fail
hg add b/b

echo % should succeed
hg add b

echo % should still fail - maybe
hg add b/b

exit 0