[PATCH v2] unpack-trees: don't update files with CE_WT_REMOVE set

[David Turner <dturner@twopensource.com>]

Don't update files in the worktree from cache entries which are
flagged with CE_WT_REMOVE.

When a user does a sparse checkout, git removes files that are marked
with CE_WT_REMOVE (because they are out-of-scope for the sparse
checkout). If those files are also marked CE_UPDATE (for instance,
because they differ in the branch that is being checked out and the
outgoing branch), git would previously recreate them.  This patch
prevents them from being recreated.

These erroneously-created files would also interfere with merges,
causing pre-merge revisions of out-of-scope files to appear in the
worktree.

Signed-off-by: Anatole Shaw <git-devel@omni.poc.net>
Signed-off-by: David Turner <dturner@twopensource.com>
---
 t/t1090-sparse-checkout-scope.sh | 52 ++++++++++++++++++++++++++++++++++++++++
 unpack-trees.c                   |  2 +-
 2 files changed, 53 insertions(+), 1 deletion(-)
 create mode 100755 t/t1090-sparse-checkout-scope.sh

diff --git a/t/t1090-sparse-checkout-scope.sh b/t/t1090-sparse-checkout-scope.sh
new file mode 100755
index 0000000..1f61eb3
--- /dev/null
+++ b/t/t1090-sparse-checkout-scope.sh
@@ -0,0 +1,52 @@
+#!/bin/sh
+
+test_description='sparse checkout scope tests'
+
+. ./test-lib.sh
+
+test_expect_success 'setup' '
+	echo "initial" >a &&
+	echo "initial" >b &&
+	echo "initial" >c &&
+	git add a b c &&
+	git commit -m "initial commit"
+'
+
+test_expect_success 'create feature branch' '
+	git checkout -b feature &&
+	echo "modified" >b &&
+	echo "modified" >c &&
+	git add b c &&
+	git commit -m "modification"
+'
+
+test_expect_success 'perform sparse checkout of master' '
+	git config --local --bool core.sparsecheckout true &&
+	echo "!/*" >.git/info/sparse-checkout &&
+	echo "/a" >>.git/info/sparse-checkout &&
+	echo "/c" >>.git/info/sparse-checkout &&
+	git checkout master &&
+	test_path_is_file a &&
+	test_path_is_missing b &&
+	test_path_is_file c
+'
+
+test_expect_success 'merge feature branch into sparse checkout of master' '
+	git merge feature &&
+	test_path_is_file a &&
+	test_path_is_missing b &&
+	test_path_is_file c &&
+	test "$(cat c)" = "modified"
+'
+
+test_expect_success 'return to full checkout of master' '
+	git checkout feature &&
+	echo "/*" >.git/info/sparse-checkout &&
+	git checkout master &&
+	test_path_is_file a &&
+	test_path_is_file b &&
+	test_path_is_file c &&
+	test "$(cat b)" = "modified"
+'
+
+test_done
diff --git a/unpack-trees.c b/unpack-trees.c
index 2927660..11a5300 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -223,7 +223,7 @@ static int check_updates(struct unpack_trees_options *o)
 	for (i = 0; i < index->cache_nr; i++) {
 		struct cache_entry *ce = index->cache[i];
 
-		if (ce->ce_flags & CE_UPDATE) {
+		if (ce->ce_flags & CE_UPDATE && !(ce->ce_flags & CE_WT_REMOVE)) {
 			display_progress(progress, ++cnt);
 			ce->ce_flags &= ~CE_UPDATE;
 			if (o->update && !o->dry_run) {
-- 
2.0.4.315.gad8727a-twtrsrc