t7111: check that reset options work as described in the tables

Some previous patches added some tables to the "git reset"
documentation. These tables describe the behavior of "git reset"
depending on the option it is passed and the state of the files
in the working tree, the index, HEAD and the target commit.

This patch adds some tests to make sure that the tables describe
the behavior of "git reset".

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t7111-reset-table.sh

@@ -0,0 +1,113 @@
+#!/bin/sh
+#
+# Copyright (c) 2010 Christian Couder
+#
+
+test_description='Tests to check that "reset" options follow a known table'
+
+. ./test-lib.sh
+
+
+test_expect_success 'creating initial commits' '
+    test_commit E file1 &&
+    test_commit D file1 &&
+    test_commit C file1
+'
+
+while read W1 I1 H1 T opt W2 I2 H2
+do
+    test_expect_success "check: $W1 $I1 $H1 $T --$opt $W2 $I2 $H2" '
+	git reset --hard C &&
+	if test "$I1" != "$H1"
+	then
+	    echo "$I1" >file1 &&
+	    git add file1
+	fi &&
+	if test "$W1" != "$I1"
+	then
+	    echo "$W1" >file1
+	fi &&
+	if test "$W2" != "XXXXX"
+	then
+	    git reset --$opt $T &&
+	    test "$(cat file1)" = "$W2" &&
+	    git checkout-index -f -- file1 &&
+	    test "$(cat file1)" = "$I2" &&
+	    git checkout -f HEAD -- file1 &&
+	    test "$(cat file1)" = "$H2"
+	else
+	    test_must_fail git reset --$opt $T
+	fi
+    '
+done <<\EOF
+A B C D soft   A B D
+A B C D mixed  A D D
+A B C D hard   D D D
+A B C D merge  XXXXX
+A B C C soft   A B C
+A B C C mixed  A C C
+A B C C hard   C C C
+A B C C merge  XXXXX
+B B C D soft   B B D
+B B C D mixed  B D D
+B B C D hard   D D D
+B B C D merge  D D D
+B B C C soft   B B C
+B B C C mixed  B C C
+B B C C hard   C C C
+B B C C merge  C C C
+B C C D soft   B C D
+B C C D mixed  B D D
+B C C D hard   D D D
+B C C D merge  XXXXX
+B C C C soft   B C C
+B C C C mixed  B C C
+B C C C hard   C C C
+B C C C merge  B C C
+EOF
+
+test_expect_success 'setting up branches to test with unmerged entries' '
+    git reset --hard C &&
+    git branch branch1 &&
+    git branch branch2 &&
+    git checkout branch1 &&
+    test_commit B1 file1 &&
+    git checkout branch2 &&
+    test_commit B2 file1
+'
+
+while read W1 I1 H1 T opt W2 I2 H2
+do
+    test_expect_success "check: $W1 $I1 $H1 $T --$opt $W2 $I2 $H2" '
+	git reset --hard B2 &&
+	test_must_fail git merge branch1 &&
+	cat file1 >X_file1 &&
+	if test "$W2" != "XXXXX"
+	then
+	    git reset --$opt $T &&
+	    if test "$W2" = "X"
+	    then
+		test_cmp file1 X_file1
+	    else
+		test "$(cat file1)" = "$W2"
+	    fi &&
+	    git checkout-index -f -- file1 &&
+	    test "$(cat file1)" = "$I2" &&
+	    git checkout -f HEAD -- file1 &&
+	    test "$(cat file1)" = "$H2"
+	else
+	    test_must_fail git reset --$opt $T
+	fi
+    '
+done <<\EOF
+X U C D soft   XXXXX
+X U C D mixed  X D D
+X U C D hard   D D D
+X U C D merge  D D D
+X U C C soft   XXXXX
+X U C C mixed  X C C
+X U C C hard   C C C
+X U C C merge  C C C
+EOF
+
+test_done