[PATCH 3/5] tree_entry_interesting: turn to match_pathspec if wildcard is present

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

A pathspec with wildcard usually requires full path to do
matching. When full path is found, match_pathspec() can do the job
pretty well (actually it can utilize pathspec_item.has_wildcard, but
that's another matter).

So if tree_entry_interesting() finds that there is wildcard in any
pathspec, it just skips all of its optimizations, tries to make full
path and pass to match_pathspec().

The implementation is pretty naive. Maybe with some pattern analysis,
we can do some early tree cutting.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
 t/t4010-diff-pathspec.sh |   14 ++++++++++++++
 tree-walk.c              |   18 ++++++++++++++++++
 2 files changed, 32 insertions(+), 0 deletions(-)

diff --git a/t/t4010-diff-pathspec.sh b/t/t4010-diff-pathspec.sh
index 94df7ae..4b120f8 100755
--- a/t/t4010-diff-pathspec.sh
+++ b/t/t4010-diff-pathspec.sh
@@ -70,4 +70,18 @@ test_expect_success 'diff-tree pathspec' '
 	test_cmp expected current
 '
 
+EMPTY_TREE=4b825dc642cb6eb9a060e54bf8d69288fbee4904
+
+test_expect_success 'diff-tree with wildcard shows dir also matches' '
+	git diff-tree --name-only $EMPTY_TREE $tree -- "f*" >result &&
+	echo file0 >expected &&
+	test_cmp expected result
+'
+
+test_expect_success 'diff-tree -r with wildcard' '
+	git diff-tree -r --name-only $EMPTY_TREE $tree -- "*file1" >result &&
+	echo path1/file1 >expected &&
+	test_cmp expected result
+'
+
 test_done
diff --git a/tree-walk.c b/tree-walk.c
index 01168ea..bc8c9bd 100644
--- a/tree-walk.c
+++ b/tree-walk.c
@@ -2,6 +2,7 @@
 #include "tree-walk.h"
 #include "unpack-trees.h"
 #include "tree.h"
+#include "dir.h"
 
 static const char *get_mode(const char *str, unsigned int *modep)
 {
@@ -478,6 +479,23 @@ int tree_entry_interesting(const struct name_entry *entry,
 
 	pathlen = tree_entry_len(entry->path, entry->sha1);
 
+	if (ps->has_wildcard) {
+		static char full_path[PATH_MAX];
+
+		/*
+		 * If it's recursive diff, directories are
+		 * intermediate step before ending up to a file.
+		 * Let it pass and we can match the files within
+		 * later.
+		 */
+		if (ps->tree_recursive_diff && S_ISDIR(entry->mode))
+			return 1;
+
+		memcpy(full_path, base, baselen);
+		memcpy(full_path+baselen, entry->path, pathlen+1);
+		return match_pathspec(ps->raw, full_path, baselen+pathlen, 0, NULL) > 0;
+	}
+
 	for (i = 0; i < ps->nr; i++) {
 		const char *match = ps->raw[i];
 		int matchlen = ps->items[i].len;
-- 
1.7.1.rc1.70.g788ca