bundlerepo: move temp bundle creation to a separate function

A future patch will refactor certain parts of bundlerepo initiatlization such
that we need to create temp bundles from another function. Let's move this to
another function to support that.

Differential Revision: https://phab.mercurial-scm.org/D288

mercurial/bundlerepo.py

@@ -264,24 +264,6 b' def _getfilestarts(bundle):'
 
 class bundlerepository(localrepo.localrepository):
     def __init__(self, ui, path, bundlename):
-        def _writetempbundle(read, suffix, header=''):
-            """Write a temporary file to disk
-
-            This is closure because we need to make sure this tracked by
-            self.tempfile for cleanup purposes."""
-            fdtemp, temp = self.vfs.mkstemp(prefix="hg-bundle-",
-                                            suffix=".hg10un")
-            self.tempfile = temp
-
-            with os.fdopen(fdtemp, pycompat.sysstr('wb')) as fptemp:
-                fptemp.write(header)
-                while True:
-                    chunk = read(2**18)
-                    if not chunk:
-                        break
-                    fptemp.write(chunk)
-
-            return self.vfs.open(self.tempfile, mode="rb")
         self._tempparent = None
         try:
             localrepo.localrepository.__init__(self, ui, path)
@@ -314,7 +296,7 b' class bundlerepository(localrepo.localre'
                         msg = _('Unsupported changegroup version: %s')
                         raise error.Abort(msg % version)
                     if self.bundle.compressed():
-                        cgstream = _writetempbundle(part.read,
+                        cgstream = self._writetempbundle(part.read,
                                                     ".cg%sun" % version)
 
             if cgstream is None:
@@ -324,7 +306,8 b' class bundlerepository(localrepo.localre'
             self.bundle = changegroup.getunbundler(version, cgstream, 'UN')
 
         elif self.bundle.compressed():
-            f = _writetempbundle(self.bundle.read, '.hg10un', header='HG10UN')
+            f = self._writetempbundle(self.bundle.read, '.hg10un',
+                                      header='HG10UN')
             self.bundlefile = self.bundle = exchange.readbundle(ui, f,
                                                                 bundlename,
                                                                 self.vfs)
@@ -336,6 +319,23 b' class bundlerepository(localrepo.localre'
         phases.retractboundary(self, None, phases.draft,
                                [ctx.node() for ctx in self[self.firstnewrev:]])
 
+    def _writetempbundle(self, readfn, suffix, header=''):
+        """Write a temporary file to disk
+        """
+        fdtemp, temp = self.vfs.mkstemp(prefix="hg-bundle-",
+                                        suffix=".hg10un")
+        self.tempfile = temp
+
+        with os.fdopen(fdtemp, pycompat.sysstr('wb')) as fptemp:
+            fptemp.write(header)
+            while True:
+                chunk = readfn(2**18)
+                if not chunk:
+                    break
+                fptemp.write(chunk)
+
+        return self.vfs.open(self.tempfile, mode="rb")
+
     @localrepo.unfilteredpropertycache
     def _phasecache(self):
         return bundlephasecache(self, self._phasedefaults)