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
# basic test for hg debugrebuildstate
hg init repo
cd repo
touch foo bar
hg ci -Am 'add foo bar'
touch baz
hg add baz
hg rm bar
echo '% state dump'
hg debugstate | cut -b 1-16,35- | sort
echo '% status'
hg st -A
hg debugrebuildstate
echo '% state dump'
hg debugstate | cut -b 1-16,35- | sort
echo '% status'
hg st -A