[PATCH 2/7] Fix ignoring of pathspecs with rev-list --objects

[Elijah Newren <newren@gmail.com>]

When traversing commits, the selection of commits would heed the list of
pathspecs passed, but subsequent walking of the trees of those commits
would not.  This resulted in 'rev-list --objects HEAD -- <paths>'
displaying objects at unwanted paths.

Have process_tree() call tree_entry_interesting() to determine which paths
are interesting and should be walked.

Naturally, this change can provide a large speedup when paths are specified
together with --objects, since many tree entries are now correctly ignored.
Interestingly, though, this change also gives me a small (~1%) but
repeatable speedup even when no paths are specified with --objects.

Signed-off-by: Elijah Newren <newren@gmail.com>
---
 diff.h                   |    1 +
 list-objects.c           |   20 +++++++++++++++++++-
 t/t6000-rev-list-misc.sh |    2 +-
 tree-diff.c              |    2 +-
 4 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/diff.h b/diff.h
index 6fff024..35130b8 100644
--- a/diff.h
+++ b/diff.h
@@ -169,6 +169,7 @@ extern int diff_tree_sha1(const unsigned char *old, const unsigned char *new,
 			  const char *base, struct diff_options *opt);
 extern int diff_root_tree_sha1(const unsigned char *new, const char *base,
                                struct diff_options *opt);
+extern int tree_entry_interesting(struct tree_desc *desc, const char *base, int baselen, struct diff_options *opt);
 
 struct combine_diff_path {
 	struct combine_diff_path *next;
diff --git a/list-objects.c b/list-objects.c
index 8953548..daa50bf 100644
--- a/list-objects.c
+++ b/list-objects.c
@@ -67,6 +67,7 @@ static void process_tree(struct rev_info *revs,
 	struct tree_desc desc;
 	struct name_entry entry;
 	struct name_path me;
+	int all_interesting = (revs->diffopt.nr_paths == 0);
 
 	if (!revs->tree_objects)
 		return;
@@ -84,7 +85,24 @@ static void process_tree(struct rev_info *revs,
 
 	init_tree_desc(&desc, tree->buffer, tree->size);
 
-	while (tree_entry(&desc, &entry)) {
+	for (; desc.size; update_tree_entry(&desc)) {
+		entry = desc.entry;
+
+		if (!all_interesting) {
+			char *full_path = path_name(path, name);
+			int full_path_len = strlen(full_path);
+			int showit = tree_entry_interesting(&desc, full_path, full_path_len,
+							    &revs->diffopt);
+			free(full_path);
+
+			if (showit < 0)
+				break;
+			else if (!showit)
+				continue;
+			else if (showit == 2)
+				all_interesting = 1;
+		}
+
 		if (S_ISDIR(entry.mode))
 			process_tree(revs,
 				     lookup_tree(entry.sha1),
diff --git a/t/t6000-rev-list-misc.sh b/t/t6000-rev-list-misc.sh
index 2c403ac..1bc395c 100755
--- a/t/t6000-rev-list-misc.sh
+++ b/t/t6000-rev-list-misc.sh
@@ -12,7 +12,7 @@ test_expect_success setup '
 	git commit -mone
 '
 
-test_expect_failure 'rev-list --objects heeds pathspecs' '
+test_expect_success 'rev-list --objects heeds pathspecs' '
 
 	git rev-list --objects HEAD -- wanted_file >output &&
 	grep wanted_file output &&
diff --git a/tree-diff.c b/tree-diff.c
index cd659c6..2fb670b 100644
--- a/tree-diff.c
+++ b/tree-diff.c
@@ -91,7 +91,7 @@ static int compare_tree_entry(struct tree_desc *t1, struct tree_desc *t2, const
  *  - zero for no
  *  - negative for "no, and no subsequent entries will be either"
  */
-static int tree_entry_interesting(struct tree_desc *desc, const char *base, int baselen, struct diff_options *opt)
+int tree_entry_interesting(struct tree_desc *desc, const char *base, int baselen, struct diff_options *opt)
 {
 	const char *path;
 	const unsigned char *sha1;
-- 
1.7.2.2.39.gf7e23