rebase -i: handle --continue more like non-interactive rebase

Non-interactive rebase requires the working tree to be clean, but
applies what is in the index without requiring the user to do it
herself.  Imitate that, but (since we are interactive, after all)
fire up an editor with the commit message.

It also fixes a subtle bug: a forgotten "continue" was removed, which
led to an infinite loop when continuing without remaining patches.

Both issues noticed by Frank Lichtenheld.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

git-rebase--interactive.sh

@@ -59,6 +59,10 @@ make_patch () {
 }
 
 die_with_patch () {
+	test -f "$DOTEST"/message ||
+		git cat-file commit $sha1 | sed "1,/^$/d" > "$DOTEST"/message
+	test -f "$DOTEST"/author-script ||
+		get_author_ident_from_commit $sha1 > "$DOTEST"/author-script
 	make_patch "$1"
 	die "$2"
 }
@@ -140,10 +144,7 @@ pick_one_preserving_merges () {
 			if ! git merge $STRATEGY -m "$msg" $new_parents
 			then
 				echo "$msg" > "$GIT_DIR"/MERGE_MSG
-				warn Error redoing merge $sha1
-				warn
-				warn After fixup, please use
-				die "$author_script git commit"
+				die Error redoing merge $sha1
 			fi
 			;;
 		*)
@@ -154,11 +155,12 @@ pick_one_preserving_merges () {
 }
 
 do_next () {
+	test -f "$DOTEST"/message && rm "$DOTEST"/message
+	test -f "$DOTEST"/author-script && rm "$DOTEST"/author-script
 	read command sha1 rest < "$TODO"
 	case "$command" in
 	\#|'')
 		mark_action_done
-		continue
 		;;
 	pick)
 		comment_for_reflog pick
@@ -201,6 +203,7 @@ do_next () {
 		git cat-file commit $sha1 | sed -e '1,/^$/d' >> "$MSG"
 		git reset --soft HEAD^
 		author_script=$(get_author_ident_from_commit $sha1)
+		echo "$author_script" > "$DOTEST"/author-script
 		case $failed in
 		f)
 			# This is like --amend, but with a different message
@@ -212,10 +215,6 @@ do_next () {
 			cp "$MSG" "$GIT_DIR"/MERGE_MSG
 			warn
 			warn "Could not apply $sha1... $rest"
-			warn "After you fixed that, commit the result with"
-			warn
-			warn "  $(echo $author_script | tr '\012' ' ') \\"
-			warn "	  git commit -F \"$GIT_DIR\"/MERGE_MSG -e"
 			die_with_patch $sha1 ""
 		esac
 		;;
@@ -265,6 +264,15 @@ do
 
 		test -d "$DOTEST" || die "No interactive rebase running"
 
+		# commit if necessary
+		git rev-parse --verify HEAD > /dev/null &&
+		git update-index --refresh &&
+		git diff-files --quiet &&
+		! git diff-index --cached --quiet HEAD &&
+		. "$DOTEST"/author-script &&
+		export GIT_AUTHOR_NAME GIT_AUTHOR_NAME GIT_AUTHOR_DATE &&
+		git commit -F "$DOTEST"/message -e
+
 		require_clean_work_tree
 		do_rest
 		;;

t/t3404-rebase-interactive.sh

@@ -63,7 +63,10 @@ test_expect_success 'setup' '
 
 cat > fake-editor.sh << EOF
 #!/bin/sh
-test "\$1" = .git/COMMIT_EDITMSG && exit
+test "\$1" = .git/COMMIT_EDITMSG && {
+	test -z "\$FAKE_COMMIT_MESSAGE" || echo "\$FAKE_COMMIT_MESSAGE" > "\$1"
+	exit
+}
 test -z "\$FAKE_LINES" && exit
 grep -v "^#" < "\$1" > "\$1".tmp
 rm "\$1"
@@ -181,11 +184,22 @@ test_expect_success 'preserve merges with -p' '
 	echo C > file1 &&
 	test_tick &&
 	git commit -m K file1 &&
+	test_tick &&
 	git rebase -i -p --onto branch1 master &&
 	test $(git rev-parse HEAD^^2) = $(git rev-parse to-be-preserved) &&
 	test $(git rev-parse HEAD~3) = $(git rev-parse branch1) &&
 	test $(git show HEAD:file1) = C &&
 	test $(git show HEAD~2:file1) = B
 '
 
+test_expect_success '--continue tries to commit' '
+	test_tick &&
+	! git rebase -i --onto new-branch1 HEAD^ &&
+	echo resolved > file1 &&
+	git add file1 &&
+	FAKE_COMMIT_MESSAGE="chouette!" git rebase --continue &&
+	test $(git rev-parse HEAD^) = $(git rev-parse new-branch1) &&
+	git show HEAD | grep chouette
+'
+
 test_done