# HG changeset patch
# User Yuya Nishihara <yuya@tcha.org>
# Date 1478611342 -32400
# Node ID ad56204f733ec94e3aceaf0ecd636a05d018a3a3
# Parent  a1259e502bdf1188df75e5ef6b1096f676028623
hook: flush stdout before restoring stderr redirection

There was a similar issue to 8b011ededfb2. If an in-process hook writes
to stdout, the data may be buffered. In which case, stdout must be flushed
before restoring its file descriptor. Otherwise, remaining data would be sent
over the ssh wire and corrupts the protocol.

Note that this is a different redirection from the one I've just removed.

diff -r a1259e502bdf -r ad56204f733e mercurial/hook.py
--- a/mercurial/hook.py	Thu Oct 20 22:39:59 2016 +0900
+++ b/mercurial/hook.py	Tue Nov 08 22:22:22 2016 +0900
@@ -258,6 +258,7 @@
             sys.stderr.flush()
     finally:
         if _redirect and oldstdout >= 0:
+            sys.__stdout__.flush()  # write hook output to stderr fd
             os.dup2(oldstdout, stdoutno)
             os.close(oldstdout)
 
diff -r a1259e502bdf -r ad56204f733e tests/test-ssh.t
--- a/tests/test-ssh.t	Thu Oct 20 22:39:59 2016 +0900
+++ b/tests/test-ssh.t	Tue Nov 08 22:22:22 2016 +0900
@@ -265,8 +265,17 @@
   > sys.stdout.write("KABOOM\n")
   > EOF
 
-  $ echo '[hooks]' >> ../remote/.hg/hgrc
-  $ echo "changegroup.stdout = python $TESTTMP/badhook" >> ../remote/.hg/hgrc
+  $ cat <<EOF > $TESTTMP/badpyhook.py
+  > import sys
+  > def hook(ui, repo, hooktype, **kwargs):
+  >     sys.stdout.write("KABOOM IN PROCESS\n")
+  > EOF
+
+  $ cat <<EOF >> ../remote/.hg/hgrc
+  > [hooks]
+  > changegroup.stdout = python $TESTTMP/badhook
+  > changegroup.pystdout = python:$TESTTMP/badpyhook.py:hook
+  > EOF
   $ echo r > r
   $ hg ci -A -m z r
 
@@ -281,6 +290,7 @@
   remote: adding file changes
   remote: added 1 changesets with 1 changes to 1 files
   remote: KABOOM
+  remote: KABOOM IN PROCESS
   $ hg -R ../remote heads
   changeset:   5:1383141674ec
   tag:         tip
@@ -447,6 +457,7 @@
   remote: adding file changes
   remote: added 1 changesets with 1 changes to 1 files
   remote: KABOOM
+  remote: KABOOM IN PROCESS
   local stdout
 
 debug output