convert: add support to common commandline to access stdin of the process

hgext/convert/common.py

@@ -254,7 +254,7 b' class commandline(object):'
     def postrun(self):
         pass
 
-    def _cmdline(self, cmd, *args, **kwargs):
+    def _cmdline(self, cmd, closestdin, *args, **kwargs):
         cmdline = [self.command, cmd] + list(args)
         for k, v in kwargs.iteritems():
             if len(k) == 1:
@@ -271,16 +271,23 b' class commandline(object):'
         cmdline = [util.shellquote(arg) for arg in cmdline]
         if not self.ui.debugflag:
             cmdline += ['2>', util.nulldev]
-        cmdline += ['<', util.nulldev]
+        if closestdin:
+            cmdline += ['<', util.nulldev]
         cmdline = ' '.join(cmdline)
         return cmdline
 
     def _run(self, cmd, *args, **kwargs):
-        cmdline = self._cmdline(cmd, *args, **kwargs)
+        return self._dorun(util.popen, cmd, True, *args, **kwargs)
+
+    def _run2(self, cmd, *args, **kwargs):
+        return self._dorun(util.popen2, cmd, False, *args, **kwargs)
+
+    def _dorun(self, openfunc, cmd, closestdin, *args, **kwargs):
+        cmdline = self._cmdline(cmd, closestdin, *args, **kwargs)
         self.ui.debug('running: %s\n' % (cmdline,))
         self.prerun()
         try:
-            return util.popen(cmdline)
+            return openfunc(cmdline)
         finally:
             self.postrun()
 
@@ -336,8 +343,9 b' class commandline(object):'
         self._argmax = self._argmax / 2 - 1
         return self._argmax
 
-    def limit_arglist(self, arglist, cmd, *args, **kwargs):
-        limit = self.getargmax() - len(self._cmdline(cmd, *args, **kwargs))
+    def limit_arglist(self, arglist, cmd, closestdin, *args, **kwargs):
+        cmdlen = len(self._cmdline(cmd, closestdin, *args, **kwargs))
+        limit = self.getargmax() - cmdlen
         bytes = 0
         fl = []
         for fn in arglist:
@@ -353,7 +361,7 b' class commandline(object):'
             yield fl
 
     def xargs(self, arglist, cmd, *args, **kwargs):
-        for l in self.limit_arglist(arglist, cmd, *args, **kwargs):
+        for l in self.limit_arglist(arglist, cmd, True, *args, **kwargs):
             self.run0(cmd, *(list(args) + l), **kwargs)
 
 class mapfile(dict):