--- a/Plugins/VcsPlugins/vcsMercurial/hg.py	Wed Mar 08 10:49:20 2017 +0100
+++ b/Plugins/VcsPlugins/vcsMercurial/hg.py	Wed Mar 08 21:52:37 2017 +0100
@@ -1808,6 +1808,8 @@
                                              self.hgGetBookmarksList(repodir))
             if dlg.exec_() == QDialog.Accepted:
                 rev1, rev2 = dlg.getRevisions()
+            else:
+                return
         elif revisions:
             rev1, rev2 = revisions[0], revisions[1]
         else: