Merge branch 'mz/reset-misc'

Various 'reset' optimizations and clean-ups, followed by a change
to allow "git reset" to work even on an unborn branch.

* mz/reset-misc:
  reset: update documentation to require only tree-ish with paths
  reset [--mixed]: use diff-based reset whether or not pathspec was given
  reset: allow reset on unborn branch
  reset $sha1 $pathspec: require $sha1 only to be treeish
  reset.c: inline update_index_refresh()
  reset.c: finish entire cmd_reset() whether or not pathspec is given
  reset [--mixed]: only write index file once
  reset.c: move lock, write and commit out of update_index_refresh()
  reset.c: move update_index_refresh() call out of read_from_tree()
  reset.c: replace switch by if-else
  reset: avoid redundant error message
  reset --keep: only write index file once
  reset.c: share call to die_if_unmerged_cache()
  reset.c: extract function for updating {ORIG_,}HEAD
  reset.c: remove unnecessary variable 'i'
  reset.c: extract function for parsing arguments
  reset: don't allow "git reset -- $pathspec" in bare repo
  reset.c: pass pathspec around instead of (prefix, argv) pair
  reset $pathspec: exit with code 0 if successful
  reset $pathspec: no need to discard index

3 files changed, 73 insertions, 7 deletions

diff --git a/t/t2013-checkout-submodule.sh b/t/t2013-checkout-submodule.sh
index 70edbb33e..06b18f8bc 100755
--- a/t/t2013-checkout-submodule.sh
+++ b/t/t2013-checkout-submodule.sh
@@ -23,7 +23,7 @@ test_expect_success '"reset <submodule>" updates the index' '
 	git update-index --refresh &&
 	git diff-files --quiet &&
 	git diff-index --quiet --cached HEAD &&
-	test_must_fail git reset HEAD^ submodule &&
+	git reset HEAD^ submodule &&
 	test_must_fail git diff-files --quiet &&
 	git reset submodule &&
 	git diff-files --quiet
diff --git a/t/t7102-reset.sh b/t/t7102-reset.sh
index b096dc88c..1fa2a5fc2 100755
--- a/t/t7102-reset.sh
+++ b/t/t7102-reset.sh
@@ -388,7 +388,8 @@ test_expect_success 'test --mixed <paths>' '
 	echo 4 > file4 &&
 	echo 5 > file1 &&
 	git add file1 file3 file4 &&
-	test_must_fail git reset HEAD -- file1 file2 file3 &&
+	git reset HEAD -- file1 file2 file3 &&
+	test_must_fail git diff --quiet &&
 	git diff > output &&
 	test_cmp output expect &&
 	git diff --cached > output &&
@@ -402,7 +403,8 @@ test_expect_success 'test resetting the index at give paths' '
 	>sub/file2 &&
 	git update-index --add sub/file1 sub/file2 &&
 	T=$(git write-tree) &&
-	test_must_fail git reset HEAD sub/file2 &&
+	git reset HEAD sub/file2 &&
+	test_must_fail git diff --quiet &&
 	U=$(git write-tree) &&
 	echo "$T" &&
 	echo "$U" &&
@@ -440,7 +442,8 @@ test_expect_success 'resetting specific path that is unmerged' '
 		echo "100644 $F3 3	file2"
 	} | git update-index --index-info &&
 	git ls-files -u &&
-	test_must_fail git reset HEAD file2 &&
+	git reset HEAD file2 &&
+	test_must_fail git diff --quiet &&
 	git diff-index --exit-code --cached HEAD
 '
 
@@ -449,7 +452,8 @@ test_expect_success 'disambiguation (1)' '
 	git reset --hard &&
 	>secondfile &&
 	git add secondfile &&
-	test_must_fail git reset secondfile &&
+	git reset secondfile &&
+	test_must_fail git diff --quiet -- secondfile &&
 	test -z "$(git diff --cached --name-only)" &&
 	test -f secondfile &&
 	test ! -s secondfile
@@ -474,7 +478,8 @@ test_expect_success 'disambiguation (3)' '
 	>secondfile &&
 	git add secondfile &&
 	rm -f secondfile &&
-	test_must_fail git reset HEAD secondfile &&
+	git reset HEAD secondfile &&
+	test_must_fail git diff --quiet &&
 	test -z "$(git diff --cached --name-only)" &&
 	test ! -f secondfile
 
@@ -486,9 +491,18 @@ test_expect_success 'disambiguation (4)' '
 	>secondfile &&
 	git add secondfile &&
 	rm -f secondfile &&
-	test_must_fail git reset -- secondfile &&
+	git reset -- secondfile &&
+	test_must_fail git diff --quiet &&
 	test -z "$(git diff --cached --name-only)" &&
 	test ! -f secondfile
 '
 
+test_expect_success 'reset with paths accepts tree' '
+	# for simpler tests, drop last commit containing added files
+	git reset --hard HEAD^ &&
+	git reset HEAD^^{tree} -- . &&
+	git diff --cached HEAD^ --exit-code &&
+	git diff HEAD --exit-code
+'
+
 test_done
diff --git a/t/t7106-reset-unborn-branch.sh b/t/t7106-reset-unborn-branch.sh
new file mode 100755
index 000000000..8062cf502
--- /dev/null
+++ b/t/t7106-reset-unborn-branch.sh
@@ -0,0 +1,52 @@
+#!/bin/sh
+
+test_description='git reset should work on unborn branch'
+. ./test-lib.sh
+
+test_expect_success 'setup' '
+	echo a >a &&
+	echo b >b
+'
+
+test_expect_success 'reset' '
+	git add a b &&
+	git reset &&
+	test "$(git ls-files)" = ""
+'
+
+test_expect_success 'reset HEAD' '
+	rm .git/index &&
+	git add a b &&
+	test_must_fail git reset HEAD
+'
+
+test_expect_success 'reset $file' '
+	rm .git/index &&
+	git add a b &&
+	git reset a &&
+	test "$(git ls-files)" = "b"
+'
+
+test_expect_success 'reset -p' '
+	rm .git/index &&
+	git add a &&
+	echo y | git reset -p &&
+	test "$(git ls-files)" = ""
+'
+
+test_expect_success 'reset --soft is a no-op' '
+	rm .git/index &&
+	git add a &&
+	git reset --soft
+	test "$(git ls-files)" = "a"
+'
+
+test_expect_success 'reset --hard' '
+	rm .git/index &&
+	git add a &&
+	git reset --hard &&
+	test "$(git ls-files)" = "" &&
+	test_path_is_missing a
+'
+
+test_done