t/t6022: a new test for renaming merge.

This adds a couple of tests to cover the following renaming
merge cases:

 - one side renames and the other side does not, with and without
   content conflicts.

 - both side rename to the same path, with and without content
   conflicts.

The test setup also prepares a case in which both side rename to
different destination, but currently the code collapses these
destination paths and removes the original path, which may be
wrong.  The outcome of this case is not checked by the tests in
this round.

Signed-off-by: Junio C Hamano <junkio@cox.net>

t/t6022-merge-rename.sh

@@ -0,0 +1,164 @@
+#!/bin/sh
+
+test_description='Merge-recursive merging renames'
+. ./test-lib.sh
+
+test_expect_success setup \
+'
+cat >A <<\EOF &&
+a aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
+b bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
+c cccccccccccccccccccccccccccccccccccccccccccccccc
+d dddddddddddddddddddddddddddddddddddddddddddddddd
+e eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
+f ffffffffffffffffffffffffffffffffffffffffffffffff
+g gggggggggggggggggggggggggggggggggggggggggggggggg
+h hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh
+i iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii
+j jjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjj
+k kkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkk
+l llllllllllllllllllllllllllllllllllllllllllllllll
+m mmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm
+n nnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn
+o oooooooooooooooooooooooooooooooooooooooooooooooo
+EOF
+
+cat >M <<\EOF &&
+A AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
+B BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB
+C CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
+D DDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDD
+E EEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE
+F FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
+G GGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGG
+H HHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH
+I IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII
+J JJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJ
+K KKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKK
+L LLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLL
+M MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM
+N NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
+O OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO
+EOF
+
+git add A M &&
+git commit -m initial &&
+git branch white &&
+git branch red &&
+git branch blue &&
+
+sed -e "/^g /s/.*/g : master changes a line/" <A >A+ &&
+mv A+ A &&
+git commit -a -m "master updates A" &&
+
+git checkout white &&
+sed -e "/^g /s/.*/g : white changes a line/" <A >B &&
+sed -e "/^G /s/.*/G : colored branch changes a line/" <M >N &&
+rm -f A M &&
+git update-index --add --remove A B M N &&
+git commit -m "white renames A->B, M->N" &&
+
+git checkout red &&
+sed -e "/^g /s/.*/g : red changes a line/" <A >B &&
+sed -e "/^G /s/.*/G : colored branch changes a line/" <M >N &&
+rm -f A M &&
+git update-index --add --remove A B M N &&
+git commit -m "red renames A->B, M->N" &&
+
+git checkout blue &&
+sed -e "/^g /s/.*/g : blue changes a line/" <A >C &&
+sed -e "/^G /s/.*/G : colored branch changes a line/" <M >N &&
+rm -f A M &&
+git update-index --add --remove A C M N &&
+git commit -m "blue renames A->C, M->N" &&
+
+git checkout master'
+
+test_expect_success 'pull renaming branch into unrenaming one' \
+'
+	git show-branch
+	git pull . white && {
+		echo "BAD: should have conflicted"
+		exit 1
+	}
+	git ls-files -s
+	test "$(git ls-files -u B | wc -l)" -eq 3 || {
+		echo "BAD: should have left stages for B"
+		exit 1	
+	}
+	test "$(git ls-files -s N | wc -l)" -eq 1 || {
+		echo "BAD: should have merged N"
+		exit 1	
+	}
+	sed -ne "/^g/{
+	p
+	q
+	}" B | grep master || {
+		echo "BAD: should have listed our change first"
+		exit 1
+	}
+	test "$(git diff white N | wc -l)" -eq 0 || {
+		echo "BAD: should have taken colored branch"
+		exit 1
+	}
+'
+
+test_expect_success 'pull renaming branch into another renaming one' \
+'
+	git reset --hard
+	git checkout red
+	git pull . white && {
+		echo "BAD: should have conflicted"
+		exit 1
+	}
+	test "$(git ls-files -u B | wc -l)" -eq 3 || {
+		echo "BAD: should have left stages"
+		exit 1	
+	}
+	test "$(git ls-files -s N | wc -l)" -eq 1 || {
+		echo "BAD: should have merged N"
+		exit 1	
+	}
+	sed -ne "/^g/{
+	p
+	q
+	}" B | grep red || {
+		echo "BAD: should have listed our change first"
+		exit 1
+	}
+	test "$(git diff white N | wc -l)" -eq 0 || {
+		echo "BAD: should have taken colored branch"
+		exit 1
+	}
+'
+
+test_expect_success 'pull unrenaming branch into renaming one' \
+'
+	git reset --hard
+	git show-branch
+	git pull . master && {
+		echo "BAD: should have conflicted"
+		exit 1
+	}
+	test "$(git ls-files -u B | wc -l)" -eq 3 || {
+		echo "BAD: should have left stages"
+		exit 1	
+	}
+	test "$(git ls-files -s N | wc -l)" -eq 1 || {
+		echo "BAD: should have merged N"
+		exit 1	
+	}
+	sed -ne "/^g/{
+	p
+	q
+	}" B | grep red || {
+		echo "BAD: should have listed our change first"
+		exit 1
+	}
+	test "$(git diff white N | wc -l)" -eq 0 || {
+		echo "BAD: should have taken colored branch"
+		exit 1
+	}
+'
+
+test_done