transplant: added 'HGREVISION' variable to the environment passed to the 'filter' command

Sometimes it is necessary to know the original revision ID in order to
correctly rewrite the patch or commit message when transplanting.  This
patch follows the pattern set by the existing 'HGUSER' environment variable,
and adds a test that covers both HGUSER and HGREVISION.

hgext/transplant.py

@@ -177,12 +177,11 b' class transplanter(object):'
             lock.release()
             wlock.release()
 
-    def filter(self, filter, changelog, patchfile):
+    def filter(self, filter, node, changelog, patchfile):
         '''arbitrarily rewrite changeset before applying it'''
 
         self.ui.status(_('filtering %s\n') % patchfile)
         user, date, msg = (changelog[1], changelog[2], changelog[4])
-
         fd, headerfile = tempfile.mkstemp(prefix='hg-transplant-')
         fp = os.fdopen(fd, 'w')
         fp.write("# HG changeset patch\n")
@@ -194,7 +193,9 b' class transplanter(object):'
         try:
             util.system('%s %s %s' % (filter, util.shellquote(headerfile),
                                    util.shellquote(patchfile)),
-                        environ={'HGUSER': changelog[1]},
+                        environ={'HGUSER': changelog[1],
+                                 'HGREVISION': revlog.hex(node),
+                                 },
                         onerr=util.Abort, errprefix=_('filter failed'))
             user, date, msg = self.parselog(file(headerfile))[1:4]
         finally:
@@ -209,7 +210,7 b' class transplanter(object):'
         date = "%d %d" % (time, timezone)
         extra = {'transplant_source': node}
         if filter:
-            (user, date, message) = self.filter(filter, cl, patchfile)
+            (user, date, message) = self.filter(filter, node, cl, patchfile)
 
         if log:
             # we don't translate messages inserted into commits

tests/test-transplant.t

@@ -330,6 +330,27 b' test filter with failed patch'
   [255]
   $ cd ..
 
+test environment passed to filter
+
+  $ hg init filter-environment
+  $ cd filter-environment
+  $ cat <<'EOF' >test-filter-environment
+  > #!/bin/sh
+  > echo "Transplant by $HGUSER" >> $1
+  > echo "Transplant from rev $HGREVISION" >> $1
+  > EOF
+  $ chmod +x test-filter-environment
+  $ hg transplant -s ../t --filter ./test-filter-environment 0
+  filtering * (glob)
+  applying 17ab29e464c6
+  17ab29e464c6 transplanted to 5190e68026a0
+
+  $ hg log --template '{rev} {parents} {desc}\n'
+  0  r1
+  Transplant by test
+  Transplant from rev 17ab29e464c6ca53e329470efe2a9918ac617a6f
+  $ cd ..
+
 
 test with a win32ext like setup (differing EOLs)