diff --git a/builtin/add.c b/builtin/add.c
index 393c10cbcf..dc4b42d0ad 100644
--- a/builtin/add.c
+++ b/builtin/add.c
@@ -553,8 +553,8 @@ int cmd_add(int argc, const char **argv, const char *prefix)
 		exit_status |= renormalize_tracked_files(&pathspec, flags);
 	else
 		exit_status |= add_files_to_cache(the_repository, prefix,
-						  &pathspec, include_sparse,
-						  flags);
+						  &pathspec, NULL,
+						  include_sparse, flags);
 
 	if (add_new_files)
 		exit_status |= add_files(&dir, flags);
diff --git a/builtin/checkout.c b/builtin/checkout.c
index 2e8b0d18f4..56d1828856 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -878,7 +878,8 @@ static int merge_working_tree(const struct checkout_opts *opts,
 			 * entries in the index.
 			 */
 
-			add_files_to_cache(the_repository, NULL, NULL, 0, 0);
+			add_files_to_cache(the_repository, NULL, NULL, NULL, 0,
+					   0);
 			init_merge_options(&o, the_repository);
 			o.verbosity = 0;
 			work = write_in_core_index_as_tree(the_repository);
diff --git a/builtin/commit.c b/builtin/commit.c
index b27b56c8be..8f31decc6b 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -444,7 +444,7 @@ static const char *prepare_index(const char **argv, const char *prefix,
 		repo_hold_locked_index(the_repository, &index_lock,
 				       LOCK_DIE_ON_ERROR);
 		add_files_to_cache(the_repository, also ? prefix : NULL,
-				   &pathspec, 0, 0);
+				   &pathspec, NULL, 0, 0);
 		refresh_cache_or_die(refresh_flags);
 		cache_tree_update(&the_index, WRITE_TREE_SILENT);
 		if (write_locked_index(&the_index, &index_lock, 0))
diff --git a/diff-lib.c b/diff-lib.c
index 1cd790a4d2..683f11e509 100644
--- a/diff-lib.c
+++ b/diff-lib.c
@@ -127,7 +127,16 @@ void run_diff_files(struct rev_info *revs, unsigned int option)
 		if (diff_can_quit_early(&revs->diffopt))
 			break;
 
-		if (!ce_path_match(istate, ce, &revs->prune_data, NULL))
+		/*
+		 * NEEDSWORK:
+		 * Here we filter with pathspec but the result is further
+		 * filtered out when --relative is in effect.  To end-users,
+		 * a pathspec element that matched only to paths outside the
+		 * current directory is like not matching anything at all;
+		 * the handling of ps_matched[] here may become problematic
+		 * if/when we add the "--error-unmatch" option to "git diff".
+		 */
+		if (!ce_path_match(istate, ce, &revs->prune_data, revs->ps_matched))
 			continue;
 
 		if (revs->diffopt.prefix &&
diff --git a/read-cache-ll.h b/read-cache-ll.h
index 2a50a784f0..09414afd04 100644
--- a/read-cache-ll.h
+++ b/read-cache-ll.h
@@ -480,8 +480,8 @@ extern int verify_ce_order;
 int cmp_cache_name_compare(const void *a_, const void *b_);
 
 int add_files_to_cache(struct repository *repo, const char *prefix,
-		       const struct pathspec *pathspec, int include_sparse,
-		       int flags);
+		       const struct pathspec *pathspec, char *ps_matched,
+		       int include_sparse, int flags);
 
 void overlay_tree_on_index(struct index_state *istate,
 			   const char *tree_name, const char *prefix);
diff --git a/read-cache.c b/read-cache.c
index f546cf7875..e1723ad796 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -3958,8 +3958,8 @@ static void update_callback(struct diff_queue_struct *q,
 }
 
 int add_files_to_cache(struct repository *repo, const char *prefix,
-		       const struct pathspec *pathspec, int include_sparse,
-		       int flags)
+		       const struct pathspec *pathspec, char *ps_matched,
+		       int include_sparse, int flags)
 {
 	struct update_callback_data data;
 	struct rev_info rev;
@@ -3971,8 +3971,10 @@ int add_files_to_cache(struct repository *repo, const char *prefix,
 
 	repo_init_revisions(repo, &rev, prefix);
 	setup_revisions(0, NULL, &rev, NULL);
-	if (pathspec)
+	if (pathspec) {
 		copy_pathspec(&rev.prune_data, pathspec);
+		rev.ps_matched = ps_matched;
+	}
 	rev.diffopt.output_format = DIFF_FORMAT_CALLBACK;
 	rev.diffopt.format_callback = update_callback;
 	rev.diffopt.format_callback_data = &data;
diff --git a/revision.h b/revision.h
index 94c43138bc..0e470d1df1 100644
--- a/revision.h
+++ b/revision.h
@@ -142,6 +142,7 @@ struct rev_info {
 	/* Basic information */
 	const char *prefix;
 	const char *def;
+	char *ps_matched; /* optionally record matches of prune_data */
 	struct pathspec prune_data;
 
 	/*