--- a/mercurial/sshpeer.py	Wed Feb 21 08:33:50 2018 -0800
+++ b/mercurial/sshpeer.py	Wed Feb 21 08:35:48 2018 -0800
@@ -349,6 +349,12 @@
         self._pipee = stderr
         self._caps = caps
 
+    # Commands that have a "framed" response where the first line of the
+    # response contains the length of that response.
+    _FRAMED_COMMANDS = {
+        'batch',
+    }
+
     # Begin of _basepeer interface.
 
     @util.propertycache
@@ -391,26 +397,7 @@
 
     __del__ = _cleanup
 
-    def _submitbatch(self, req):
-        rsp = self._callstream("batch", cmds=wireproto.encodebatchcmds(req))
-        available = self._getamount()
-        # TODO this response parsing is probably suboptimal for large
-        # batches with large responses.
-        toread = min(available, 1024)
-        work = rsp.read(toread)
-        available -= toread
-        chunk = work
-        while chunk:
-            while ';' in work:
-                one, work = work.split(';', 1)
-                yield wireproto.unescapearg(one)
-            toread = min(available, 1024)
-            chunk = rsp.read(toread)
-            available -= toread
-            work += chunk
-        yield wireproto.unescapearg(work)
-
-    def _sendrequest(self, cmd, args):
+    def _sendrequest(self, cmd, args, framed=False):
         if (self.ui.debugflag
             and self.ui.configbool('devel', 'debug.peer-request')):
             dbg = self.ui.debug
@@ -444,20 +431,27 @@
                 self._pipeo.write(v)
         self._pipeo.flush()
 
+        # We know exactly how many bytes are in the response. So return a proxy
+        # around the raw output stream that allows reading exactly this many
+        # bytes. Callers then can read() without fear of overrunning the
+        # response.
+        if framed:
+            amount = self._getamount()
+            return util.cappedreader(self._pipei, amount)
+
         return self._pipei
 
     def _callstream(self, cmd, **args):
         args = pycompat.byteskwargs(args)
-        return self._sendrequest(cmd, args)
+        return self._sendrequest(cmd, args, framed=cmd in self._FRAMED_COMMANDS)
 
     def _callcompressable(self, cmd, **args):
         args = pycompat.byteskwargs(args)
-        return self._sendrequest(cmd, args)
+        return self._sendrequest(cmd, args, framed=cmd in self._FRAMED_COMMANDS)
 
     def _call(self, cmd, **args):
         args = pycompat.byteskwargs(args)
-        self._sendrequest(cmd, args)
-        return self._readframed()
+        return self._sendrequest(cmd, args, framed=True).read()
 
     def _callpush(self, cmd, fp, **args):
         r = self._call(cmd, **args)