diff -r 3158052720ae -r 7cc4a9b9732a mercurial/wireprotoserver.py
--- a/mercurial/wireprotoserver.py	Sat Feb 24 12:24:03 2018 -0800
+++ b/mercurial/wireprotoserver.py	Sun Feb 25 11:16:09 2018 -0800
@@ -588,12 +588,19 @@
                                          state)
 
 class sshserver(object):
-    def __init__(self, ui, repo):
+    def __init__(self, ui, repo, logfh=None):
         self._ui = ui
         self._repo = repo
         self._fin = ui.fin
         self._fout = ui.fout
 
+        # Log write I/O to stdout and stderr if configured.
+        if logfh:
+            self._fout = util.makeloggingfileobject(
+                logfh, self._fout, 'o', logdata=True)
+            ui.ferr = util.makeloggingfileobject(
+                logfh, ui.ferr, 'e', logdata=True)
+
         hook.redirect(True)
         ui.fout = repo.ui.fout = ui.ferr