[musl] [PATCH v3 2/2] nftw: implement FTW_ACTIONRETVAL (GNU extension)

[Ismael Luceno <ismael@iodev.co.uk>]

Signed-off-by: Ismael Luceno <ismael@iodev.co.uk>
---
 include/ftw.h   |  7 +++++++
 src/misc/nftw.c | 33 +++++++++++++++++++++++----------
 2 files changed, 30 insertions(+), 10 deletions(-)

diff --git a/include/ftw.h b/include/ftw.h
index b15c062a8389..2e77dc76e11b 100644
--- a/include/ftw.h
+++ b/include/ftw.h
@@ -21,6 +21,13 @@ extern "C" {
 #define FTW_CHDIR 4
 #define FTW_DEPTH 8
 
+#define FTW_ACTIONRETVAL  16
+/* return values for callback */
+#define FTW_CONTINUE	  0
+#define FTW_STOP          1
+#define FTW_SKIP_SUBTREE  2
+#define FTW_SKIP_SIBLINGS 3
+
 struct FTW {
 	int base;
 	int level;
diff --git a/src/misc/nftw.c b/src/misc/nftw.c
index 7569a657e54e..382169f66b8b 100644
--- a/src/misc/nftw.c
+++ b/src/misc/nftw.c
@@ -26,7 +26,7 @@ static int do_nftw(char *path, int (*fn)(const char *, const struct stat *, int,
 	struct stat st;
 	struct history new;
 	int type;
-	int r;
+	int r, r2;
 	int dfd;
 	int err;
 	struct FTW lev;
@@ -72,12 +72,19 @@ static int do_nftw(char *path, int (*fn)(const char *, const struct stat *, int,
 		if (!fd_limit) close(dfd);
 	}
 
-	if (!(flags & FTW_DEPTH) && (r=fn(path, &st, type, &lev)))
-		return r;
+	r = 0;
+	if (!(flags & FTW_DEPTH) && (r=fn(path, &st, type, &lev))) {
+		if ((flags & FTW_ACTIONRETVAL)) {
+			if (r == FTW_STOP) return FTW_STOP;
+			if (r == FTW_SKIP_SUBTREE) return 0;
+			/* other values are saved for when returning */
+		} else
+			return r;
+	}
 
 	for (; h; h = h->chain)
 		if (h->dev == st.st_dev && h->ino == st.st_ino)
-			return 0;
+			return r;
 
 	if ((type == FTW_D || type == FTW_DP) && fd_limit) {
 		if (dfd < 0) {
@@ -107,9 +114,12 @@ static int do_nftw(char *path, int (*fn)(const char *, const struct stat *, int,
 				}
 				path[j]='/';
 				strcpy(path+j+1, de->d_name);
-				if ((r=do_nftw(path, fn, fd_limit-1, flags, &new))) {
+				if ((r2=do_nftw(path, fn, fd_limit-1, flags, &new))) {
+					if ((flags & FTW_ACTIONRETVAL)
+					    && r2 == FTW_SKIP_SIBLINGS)
+						break;
 					closedir(d);
-					return r;
+					return r2;
 				}
 			}
 			closedir(d);
@@ -120,10 +130,13 @@ static int do_nftw(char *path, int (*fn)(const char *, const struct stat *, int,
 	}
 
 	path[l] = 0;
-	if ((flags & FTW_DEPTH) && (r=fn(path, &st, type, &lev)))
-		return r;
-
-	return 0;
+	if (flags & FTW_DEPTH) {
+		r = fn(path, &st, type, &lev);
+		/* ignore FTW_SKIP_SUBTREE (too late), the caller is broken */
+		if ((flags & FTW_ACTIONRETVAL) && r == FTW_SKIP_SUBTREE)
+			return 0;
+	}
+	return r;
 }
 
 int nftw(const char *path, int (*fn)(const char *, const struct stat *, int, struct FTW *), int fd_limit, int flags)
-- 
2.33.0