patchunpack-trees: don't update files flagged for deletion

> 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) {

> 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.

> Thank you both for catching this. Just a small suggestion. Perhaps we
> should do this instead. apply_sparse_checkout() is the function where
> all "action" manipulation (add, delete, update files..) for sparse
> checkout occurs and it should not ask to delete and update both at the
> same time.

>
> -- 8< --
> diff --git a/unpack-trees.c b/unpack-trees.c
> index 2927660..d6cf849 100644
> --- a/unpack-trees.c
> +++ b/unpack-trees.c
> @@ -224,6 +224,9 @@ static int check_updates(struct unpack_trees_options *o)
>  		struct cache_entry *ce = index->cache[i];
>  
>  		if (ce->ce_flags & CE_UPDATE) {
> +			if (ce->ce_flags & CE_WT_REMOVE)
> +				die("BUG: both update and delete flags are set on %s",
> +				    ce->name);
>  			display_progress(progress, ++cnt);
>  			ce->ce_flags &= ~CE_UPDATE;
>  			if (o->update && !o->dry_run) {
> @@ -293,6 +296,7 @@ static int apply_sparse_checkout(struct index_state *istate,
>  		if (!(ce->ce_flags & CE_UPDATE) && verify_uptodate_sparse(ce, o))
>  			return -1;
>  		ce->ce_flags |= CE_WT_REMOVE;
> +		ce->ce_flags &= ~CE_UPDATE;
>  	}
>  	if (was_skip_worktree && !ce_skip_worktree(ce)) {
>  		if (verify_absent_sparse(ce, ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN, o))
> -- 8< --
>
> --
> Duy

> Duy Nguyen <pclouds@gmail.com> writes:
>
>> Thank you both for catching this. Just a small suggestion. Perhaps we
>> should do this instead. apply_sparse_checkout() is the function where
>> all "action" manipulation (add, delete, update files..) for sparse
>> checkout occurs and it should not ask to delete and update both at the
>> same time.
>
> Sounds good.  The first hunk may merely be a noise, but the second
> one is the true bugfix for the issue observed, I think.

> On Fri, Jul 17, 2015 at 05:19:27PM -0400, David Turner wrote:
> > 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.
> 
> Thank you both for catching this. Just a small suggestion. Perhaps we
> should do this instead. apply_sparse_checkout() is the function where
> all "action" manipulation (add, delete, update files..) for sparse
> checkout occurs and it should not ask to delete and update both at the
> same time.
> 
> -- 8< --
> diff --git a/unpack-trees.c b/unpack-trees.c
> index 2927660..d6cf849 100644
> --- a/unpack-trees.c
> +++ b/unpack-trees.c
> @@ -224,6 +224,9 @@ static int check_updates(struct unpack_trees_options *o)
>  		struct cache_entry *ce = index->cache[i];
>  
>  		if (ce->ce_flags & CE_UPDATE) {
> +			if (ce->ce_flags & CE_WT_REMOVE)
> +				die("BUG: both update and delete flags are set on %s",
> +				    ce->name);
>  			display_progress(progress, ++cnt);
>  			ce->ce_flags &= ~CE_UPDATE;
>  			if (o->update && !o->dry_run) {
> @@ -293,6 +296,7 @@ static int apply_sparse_checkout(struct index_state *istate,
>  		if (!(ce->ce_flags & CE_UPDATE) && verify_uptodate_sparse(ce, o))
>  			return -1;
>  		ce->ce_flags |= CE_WT_REMOVE;
> +		ce->ce_flags &= ~CE_UPDATE;
>  	}
>  	if (was_skip_worktree && !ce_skip_worktree(ce)) {
>  		if (verify_absent_sparse(ce, ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN, o))
> -- 8< --
> 
> --
> Duy