1 files changed, 34 insertions, 1 deletions
diff --git a/src/pkg/syscall/syscall_bsd.go b/src/pkg/syscall/syscall_bsd.go
index af563910b1..2556fa8746 100644
--- a/src/pkg/syscall/syscall_bsd.go
+++ b/src/pkg/syscall/syscall_bsd.go
@@ -68,7 +68,40 @@ func ReadDirent(fd int, buf []byte) (n int, err error) {
 	// actual system call is getdirentries64, 64 is a good guess.
 	// TODO(rsc): Can we use a single global basep for all calls?
 	var base = (*uintptr)(unsafe.Pointer(new(uint64)))
-	return Getdirentries(fd, buf, base)
+	n, err = Getdirentries(fd, buf, base)
+
+	// On OS X 10.10 Yosemite, if you have a directory that can be returned
+	// in a single getdirentries64 call (for example, a directory with one file),
+	// and you read from the directory at EOF twice, you get EOF both times:
+	//	fd = open("dir")
+	//	getdirentries64(fd) // returns data
+	//	getdirentries64(fd) // returns 0 (EOF)
+	//	getdirentries64(fd) // returns 0 (EOF)
+	//
+	// But if you remove the file in the middle between the two calls, the
+	// second call returns an error instead.
+	//	fd = open("dir")
+	//	getdirentries64(fd) // returns data
+	//	getdirentries64(fd) // returns 0 (EOF)
+	//	remove("dir/file")
+	//	getdirentries64(fd) // returns ENOENT/EINVAL
+	//
+	// Whether you get ENOENT or EINVAL depends on exactly what was
+	// in the directory. It is deterministic, just data-dependent.
+	//
+	// This only happens in small directories. A directory containing more data
+	// than fits in a 4k getdirentries64 call will return EOF correctly.
+	// (It's not clear if the criteria is that the directory be split across multiple
+	// getdirentries64 calls or that it be split across multiple file system blocks.)
+	//
+	// We could change package os to avoid the second read at EOF,
+	// and maybe we should, but that's a bit involved.
+	// For now, treat the EINVAL/ENOENT as EOF.
+	if runtime.GOOS == "darwin" && (err == EINVAL || err == ENOENT) {
+		err = nil
+	}
+
+	return
 }
 
 // Wait status is 7 bits at bottom, either 0 (exited),