Merge branch 'js/rebase-i-p'

* js/rebase-i-p:
  rebase -i -p: leave a --cc patch when a merge could not be redone
  rebase -i -p: Fix --continue after a merge could not be redone
  Show a failure of rebase -p if the merge had a conflict

git-rebase--interactive.sh

@@ -115,9 +115,18 @@ mark_action_done () {
 }
 
 make_patch () {
-	parent_sha1=$(git rev-parse --verify "$1"^) ||
-		die "Cannot get patch for $1^"
-	git diff-tree -p "$parent_sha1".."$1" > "$DOTEST"/patch
+	sha1_and_parents="$(git rev-list --parents -1 "$1")"
+	case "$sha1_and_parents" in
+	?*' '?*' '?*)
+		git diff --cc $sha1_and_parents
+		;;
+	?*' '?*)
+		git diff-tree -p "$1^!"
+		;;
+	*)
+		echo "Root commit"
+		;;
+	esac > "$DOTEST"/patch
 	test -f "$DOTEST"/message ||
 		git cat-file commit "$1" | sed "1,/^$/d" > "$DOTEST"/message
 	test -f "$DOTEST"/author-script ||
@@ -256,9 +265,8 @@ pick_one_preserving_merges () {
 				output git merge $STRATEGY -m "$msg" \
 					$new_parents
 			then
-				git rerere
 				printf "%s\n" "$msg" > "$GIT_DIR"/MERGE_MSG
-				die Error redoing merge $sha1
+				die_with_patch $sha1 "Error redoing merge $sha1"
 			fi
 			;;
 		*)

t/t3409-rebase-preserve-merges.sh

@@ -11,15 +11,23 @@ Run "git rebase -p" and check that merges are properly carried along
 GIT_AUTHOR_EMAIL=bogus_email_address
 export GIT_AUTHOR_EMAIL
 
-#echo 'Setting up:
+# Clone 1 (trivial merge):
 #
-#A1--A2  <-- origin/master
-# \   \
-#  B1--M  <-- topic
-#   \
-#    B2  <-- origin/topic
+# A1--A2  <-- origin/master
+#  \   \
+#   B1--M  <-- topic
+#    \
+#     B2  <-- origin/topic
 #
-#'
+# Clone 2 (conflicting merge):
+#
+# A1--A2--B3   <-- origin/master
+#  \       \
+#   B1------M  <-- topic
+#    \
+#     B2       <-- origin/topic
+#
+# In both cases, 'topic' is rebased onto 'origin/topic'.
 
 test_expect_success 'setup for merge-preserving rebase' \
 	'echo First > A &&
@@ -37,12 +45,19 @@ test_expect_success 'setup for merge-preserving rebase' \
 	cd clone1 &&
 	git checkout -b topic origin/topic &&
 	git merge origin/master &&
-	cd ..
+	cd .. &&
 
-	git clone ./. clone2
+	echo Fifth > B &&
+	git add B &&
+	git commit -m "Add different B" &&
+
+	git clone ./. clone2 &&
 	cd clone2 &&
 	git checkout -b topic origin/topic &&
-	git merge origin/master &&
+	test_must_fail git merge origin/master &&
+	echo Resolved > B &&
+	git add B &&
+	git commit -m "Merge origin/master into topic" &&
 	cd .. &&
 
 	git checkout topic &&
@@ -51,11 +66,30 @@ test_expect_success 'setup for merge-preserving rebase' \
 '
 
 test_expect_success 'rebase -p fakes interactive rebase' '
-	cd clone2 &&
+	(
+	cd clone1 &&
 	git fetch &&
 	git rebase -p origin/topic &&
 	test 1 = $(git rev-list --all --pretty=oneline | grep "Modify A" | wc -l) &&
 	test 1 = $(git rev-list --all --pretty=oneline | grep "Merge commit" | wc -l)
+	)
+'
+
+test_expect_success '--continue works after a conflict' '
+	(
+	cd clone2 &&
+	git fetch &&
+	test_must_fail git rebase -p origin/topic &&
+	test 2 = $(git ls-files B | wc -l) &&
+	echo Resolved again > B &&
+	test_must_fail git rebase --continue &&
+	grep "^@@@ " .git/rebase-merge/patch &&
+	git add B &&
+	git rebase --continue &&
+	test 1 = $(git rev-list --all --pretty=oneline | grep "Modify A" | wc -l) &&
+	test 1 = $(git rev-list --all --pretty=oneline | grep "Add different" | wc -l) &&
+	test 1 = $(git rev-list --all --pretty=oneline | grep "Merge origin" | wc -l)
+	)
 '
 
 test_done