Merge branch 'mm/rebase-i-exec-edit' into maint

* mm/rebase-i-exec-edit:
  rebase -i: notice and warn if "exec $cmd" modifies the index or the working tree
  rebase -i: clean error message for --continue after failed exec

git-rebase--interactive.sh

@@ -472,18 +472,24 @@ do_next () {
 		git rev-parse --verify HEAD > "$state_dir"/stopped-sha
 		${SHELL:-@SHELL_PATH@} -c "$rest" # Actual execution
 		status=$?
+		# Run in subshell because require_clean_work_tree can die.
+		dirty=f
+		(require_clean_work_tree "rebase" 2>/dev/null) || dirty=t
 		if test "$status" -ne 0
 		then
 			warn "Execution failed: $rest"
+			test "$dirty" = f ||
+			warn "and made changes to the index and/or the working tree"
+
 			warn "You can fix the problem, and then run"
 			warn
 			warn "	git rebase --continue"
 			warn
 			exit "$status"
-		fi
-		# Run in subshell because require_clean_work_tree can die.
-		if ! (require_clean_work_tree "rebase")
+		elif test "$dirty" = t
 		then
+			warn "Execution succeeded: $rest"
+			warn "but left changes to the index and/or the working tree"
 			warn "Commit or stash your changes, and then run"
 			warn
 			warn "	git rebase --continue"
@@ -647,8 +653,24 @@ continue)
 	then
 		: Nothing to commit -- skip this
 	else
+		if ! test -f "$author_script"
+		then
+			die "You have staged changes in your working tree. If these changes are meant to be
+squashed into the previous commit, run:
+
+  git commit --amend
+
+If they are meant to go into a new commit, run:
+
+  git commit
+
+In both case, once you're done, continue with:
+
+  git rebase --continue
+"
+		fi
 		. "$author_script" ||
-			die "Cannot find the author identity"
+			die "Error trying to find the author identity to amend commit"
 		current_head=
 		if test -f "$amend"
 		then

t/t3404-rebase-interactive.sh

@@ -527,6 +527,20 @@ test_expect_success 'auto-amend only edited commits after "edit"' '
 	git rebase --abort
 '
 
+test_expect_success 'clean error after failed "exec"' '
+	test_tick &&
+	test_when_finished "git rebase --abort || :" &&
+	(
+		FAKE_LINES="1 exec_false" &&
+		export FAKE_LINES &&
+		test_must_fail git rebase -i HEAD^
+	) &&
+	echo "edited again" > file7 &&
+	git add file7 &&
+	test_must_fail git rebase --continue 2>error &&
+	grep "You have staged changes in your working tree." error
+'
+
 test_expect_success 'rebase a detached HEAD' '
 	grandparent=$(git rev-parse HEAD~2) &&
 	git checkout $(git rev-parse HEAD) &&