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
# http://www.selenic.com/mercurial/bts/issue352
"$TESTDIR/hghave" eol-in-paths || exit 80
hg init foo
cd foo
A=`printf 'he\rllo'`
echo foo > "$A"
hg add
hg ci -A -m m
rm "$A"
echo foo > "hell
o"
hg add
hg ci -A -m m
echo foo > "$A"
hg debugwalk
exit 0