--- git-1.6.0.4/git-rebase.sh	2008-11-09 07:53:38.000000000 +0100
+++ git-1.6.0.4/git-rebase.sh.patched	2008-11-11 15:10:27.000000000 +0100
@@ -375,6 +375,7 @@
 # but this should be done only when upstream and onto are the same.
 mb=$(git merge-base "$onto" "$branch")
 if test "$upstream" = "$onto" && test "$mb" = "$onto" &&
+        ! (echo $git_am_opt | grep -e --whitespace ) > /dev/null &&
 	# linear history?
 	! (git rev-list --parents "$onto".."$branch" | grep " .* ") > /dev/null
 then