# HG changeset patch
# User FUJIWARA Katsunori <foozy@lares.dti.ne.jp>
# Date 2016-10-08 16:03:19
# Node ID 04f2b980df3cfb2defbd5572b205032a233e479f
# Parent  423bf74d2e5bb032dd939c96bdd767a244b5dff5

perf: omit copying from ui.ferr to ui.fout for Mercurial earlier than 1.9

Before this patch, referring ui.ferr prevents perf.py from measuring
performance with Mercurial earlier than 1.9 (or 4e1ccd4c2b6d), because
ui.ferr isn't available in such Mercurial, even though there are some
code paths for Mercurial earlier than 1.9 in perf.py.

For example, setting "_prereadsize" attribute in perfindex() and
perfnodelookup() is effective only with hg earlier than 1.8 (or
61c9bc3da402).

diff --git a/contrib/perf.py b/contrib/perf.py
--- a/contrib/perf.py
+++ b/contrib/perf.py
@@ -137,7 +137,11 @@ def gettimer(ui, opts=None):
         opts = {}
     # redirect all to stderr
     ui = ui.copy()
-    ui.fout = ui.ferr
+    uifout = safeattrsetter(ui, 'fout', ignoremissing=True)
+    if uifout:
+        # for "historical portability":
+        # ui.fout/ferr have been available since 1.9 (or 4e1ccd4c2b6d)
+        uifout.set(ui.ferr)
 
     # get a formatter
     uiformatter = getattr(ui, 'formatter', None)