mq: qrename should not touch the dirstate if src is untracked (issue2460)

hgext/mq.py

@@ -2400,7 +2400,7 b' def rename(ui, repo, patch, name=None, *'
         os.makedirs(destdir)
     util.rename(q.join(patch), absdest)
     r = q.qrepo()
-    if r:
+    if r and patch in r.dirstate:
         wctx = r[None]
         wlock = r.wlock()
         try:

tests/test-mq-qrename.t

@@ -81,3 +81,16 b' Test overlapping renames (issue2388)'
   A patchc
   R patcha
   $ cd ..
+
+Test renames with mq repo (issue2097)
+
+  $ hg init issue2097
+  $ cd issue2097
+  $ hg qnew p0
+  $ (cd .hg/patches && hg init)
+  $ hg qren p0 p1
+  $ hg debugstate --mq
+  $ hg ci --mq -mq0
+  nothing changed
+  [1]
+  $ cd ..