diff-no-index: do not reference .d_type member of struct dirent

Some platforms like AIX lack .d_type member in "struct dirent"; use the DTYPE(e) macro instead of a direct reference to e->d_type and when it yields DT_UNKNOWN, find the real type with get_dtype().

---
* get_dtype() was designed for a typical

- prepare the path in a strbuf B
- opendir(B)
- loop over readdir(B)
- do things to path (B + e->d_name)

code structure, but because this code path does not use a strbuf (instead the path given to opendir is a "const char *"), the entire thing becomes messier than necessary. get_dtype() has a short-cut to avoid having to concatenate path+e->d_name and run (l)stat() when e->d_type exists and known, but we need to open code it here.

 diff-no-index.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

index 4aeeb98cfa..88ae4cee56 100644
@@ -41,12 +41,24 @@ static int read_directory_contents(const char *path, struct string_list *list,
 
 	while ((e = readdir_skip_dot_and_dotdot(dir))) {
 		if (pathspec) {
+			int is_dir = 0;
+
 			strbuf_setlen(&match, len);
 			strbuf_addstr(&match, e->d_name);
+			if (NOT_CONSTANT(DTYPE(e)) != DT_UNKNOWN) {
+				is_dir = (DTYPE(e) == DT_DIR);
+			} else {
+				struct strbuf pathbuf = STRBUF_INIT;
+
+				strbuf_addstr(&pathbuf, path);
+				strbuf_complete(&pathbuf, '/');
+				is_dir = get_dtype(e, &pathbuf, 0) == DT_DIR;
+				strbuf_release(&pathbuf);
+			}
 
 			if (!match_leading_pathspec(NULL, pathspec,
 						    match.buf, match.len,
-						    0, NULL, e->d_type == DT_DIR ? 1 : 0))
+						    0, NULL, is_dir))
 				continue;
 		}
 

2.50.0-228-g6e205fdad9

Tested on AIX 7.3 like the previous patch just to be safe and it works as expected.

Thanks,
Collin