rebase: allow --skip to work with --merge

Now that we control the merge base selection, we won't be forced
into rolling things in that we wanted to skip beforehand.

Also, add a test to ensure this all works as intended.

Signed-off-by: Eric Wong <normalperson@yhbt.net>
Signed-off-by: Junio C Hamano <junkio@cox.net>

Documentation/git-rebase.txt

@@ -108,7 +108,6 @@ OPTIONS
 
 --skip::
 	Restart the rebasing process by skipping the current patch.
-	This does not work with the --merge option.
 
 --merge::
 	Use merging strategies to rebase.  When the recursive (default) merge

git-rebase.sh

@@ -137,7 +137,18 @@ do
 	--skip)
 		if test -d "$dotest"
 		then
-			die "--skip is not supported when using --merge"
+			prev_head="`cat $dotest/prev_head`"
+			end="`cat $dotest/end`"
+			msgnum="`cat $dotest/msgnum`"
+			msgnum=$(($msgnum + 1))
+			onto="`cat $dotest/onto`"
+			while test "$msgnum" -le "$end"
+			do
+				call_merge "$msgnum"
+				continue_merge
+			done
+			finish_rb_merge
+			exit
 		fi
 		git am -3 --skip --resolvemsg="$RESOLVEMSG"
 		exit

t/t3403-rebase-skip.sh

@@ -0,0 +1,61 @@
+#!/bin/sh
+#
+# Copyright (c) 2006 Eric Wong
+#
+
+test_description='git rebase --merge --skip tests'
+
+. ./test-lib.sh
+
+# we assume the default git-am -3 --skip strategy is tested independently
+# and always works :)
+
+if test "$no_python"; then
+	echo "Skipping: no python => no recursive merge"
+	test_done
+	exit 0
+fi
+
+test_expect_success setup '
+	echo hello > hello &&
+	git add hello &&
+	git commit -m "hello" &&
+	git branch skip-reference &&
+
+	echo world >> hello &&
+	git commit -a -m "hello world" &&
+	echo goodbye >> hello &&
+	git commit -a -m "goodbye" &&
+
+	git checkout -f skip-reference &&
+	echo moo > hello &&
+	git commit -a -m "we should skip this" &&
+	echo moo > cow &&
+	git add cow &&
+	git commit -m "this should not be skipped" &&
+	git branch pre-rebase skip-reference &&
+	git branch skip-merge skip-reference
+	'
+
+test_expect_failure 'rebase with git am -3 (default)' 'git rebase master'
+
+test_expect_success 'rebase --skip with am -3' '
+	git reset --hard HEAD &&
+	git rebase --skip
+	'
+test_expect_success 'checkout skip-merge' 'git checkout -f skip-merge'
+
+test_expect_failure 'rebase with --merge' 'git rebase --merge master'
+
+test_expect_success 'rebase --skip with --merge' '
+	git reset --hard HEAD &&
+	git rebase --skip
+	'
+
+test_expect_success 'merge and reference trees equal' \
+	'test -z "`git-diff-tree skip-merge skip-reference`"'
+
+test_debug 'gitk --all & sleep 1'
+
+test_done
+