[PATCH v4 04/16] revision.c: --indexed-objects add objects from all worktrees

["Nguyễn Thái Ngọc Duy" <pclouds@gmail.com>]

This is the result of single_worktree flag never being set (no way to up
until now). To get objects from current index only, set single_worktree.

The other add_index_objects_to_pending's caller is mark_reachable_objects()
(e.g. "git prune") which also mark objects from all indexes.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
 revision.c       | 21 +++++++++++++++++++++
 t/t5304-prune.sh |  9 +++++++++
 2 files changed, 30 insertions(+)

diff --git a/revision.c b/revision.c
index 6c46ad6c8a..f35cb49af5 100644
--- a/revision.c
+++ b/revision.c
@@ -19,6 +19,7 @@
 #include "dir.h"
 #include "cache-tree.h"
 #include "bisect.h"
+#include "worktree.h"
 
 volatile show_early_output_fn_t show_early_output;
 
@@ -1290,8 +1291,28 @@ static void do_add_index_objects_to_pending(struct rev_info *revs,
 
 void add_index_objects_to_pending(struct rev_info *revs, unsigned int flags)
 {
+	struct worktree **worktrees, **p;
+
 	read_cache();
 	do_add_index_objects_to_pending(revs, &the_index);
+
+	if (revs->single_worktree)
+		return;
+
+	worktrees = get_worktrees(0);
+	for (p = worktrees; *p; p++) {
+		struct worktree *wt = *p;
+		struct index_state istate = { NULL };
+
+		if (wt->is_current)
+			continue; /* current index already taken care of */
+
+		if (read_index_from(&istate,
+				    worktree_git_path(wt, "index")) > 0)
+			do_add_index_objects_to_pending(revs, &istate);
+		discard_index(&istate);
+	}
+	free_worktrees(worktrees);
 }
 
 static int add_parents_only(struct rev_info *revs, const char *arg_, int flags,
diff --git a/t/t5304-prune.sh b/t/t5304-prune.sh
index 133b5842b1..cba45c7be9 100755
--- a/t/t5304-prune.sh
+++ b/t/t5304-prune.sh
@@ -283,4 +283,13 @@ test_expect_success 'prune: handle alternate object database' '
 	git -C B prune
 '
 
+test_expect_success 'prune: handle index in multiple worktrees' '
+	git worktree add second-worktree &&
+	echo "new blob for second-worktree" >second-worktree/blob &&
+	git -C second-worktree add blob &&
+	git prune --expire=now &&
+	git -C second-worktree show :blob >actual &&
+	test_cmp second-worktree/blob actual
+'
+
 test_done
-- 
2.11.0.157.gd943d85