hghave: avoid a deadlock reading the child process's output
The output of `pylint` is voluminous enough that it fills the buffer on Windows,
and waited for the parent to read it out. But the parent was waiting on the
child to exit.
I'm not sure what the intent of setting `ret = -1` in the exception handler just
above this was...
--- a/tests/hghave.py Thu May 31 09:19:09 2018 -0400
+++ b/tests/hghave.py Thu May 31 22:11:47 2018 -0400
@@ -98,8 +98,8 @@
if e.errno != errno.ENOENT:
raise
ret = -1
- ret = p.wait()
- s = p.stdout.read()
+ s = p.communicate()[0]
+ ret = p.returncode
return (ignorestatus or not ret) and r.search(s)
@check("baz", "GNU Arch baz client")