dir: introduce readdir_skip_dot_and_dotdot() helper

Many places in the code were doing
    while ((d = readdir(dir)) != NULL) {
        if (is_dot_or_dotdot(d->d_name))
            continue;
        ...process d...
    }
Introduce a readdir_skip_dot_and_dotdot() helper to make that a one-liner:
    while ((d = readdir_skip_dot_and_dotdot(dir)) != NULL) {
        ...process d...
    }

This helper particularly simplifies checks for empty directories.

Also use this helper in read_cached_dir() so that our statistics are
consistent across platforms.  (In other words, read_cached_dir() should
have been using is_dot_or_dotdot() and skipping such entries, but did
not and left it to treat_path() to detect and mark such entries as
path_none.)

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/dir.h b/dir.h
index 70c750e305..6b3fac0829 100644
--- a/dir.h
+++ b/dir.h
@@ -342,6 +342,8 @@ struct dir_struct {
 	unsigned visited_directories;
 };
 
+struct dirent *readdir_skip_dot_and_dotdot(DIR *dirp);
+
 /*Count the number of slashes for string s*/
 int count_slashes(const char *s);