Return 0, nil in all io cases where an empty slice is provided

core/os/os2/file_linux.odin

@@ -201,6 +201,9 @@ _read :: proc(f: ^File_Impl, p: []byte) -> (i64, Error) {
 }
 
 _read_at :: proc(f: ^File_Impl, p: []byte, offset: i64) -> (i64, Error) {
+	if len(p) == 0 {
+		return 0, nil
+	}
 	if offset < 0 {
 		return 0, .Invalid_Offset
 	}
@@ -226,6 +229,9 @@ _write :: proc(f: ^File_Impl, p: []byte) -> (i64, Error) {
 }
 
 _write_at :: proc(f: ^File_Impl, p: []byte, offset: i64) -> (i64, Error) {
+	if len(p) == 0 {
+		return 0, nil
+	}
 	if offset < 0 {
 		return 0, .Invalid_Offset
 	}

core/os/os2/file_windows.odin

@@ -266,6 +266,11 @@ _read :: proc(f: ^File_Impl, p: []byte) -> (n: i64, err: Error) {
 }
 
 _read_internal :: proc(f: ^File_Impl, p: []byte) -> (n: i64, err: Error) {
+	length := len(p)
+	if length == 0 {
+		return
+	}
+
 	read_console :: proc(handle: win32.HANDLE, b: []byte) -> (n: int, err: Error) {
 		if len(b) == 0 {
 			return 0, nil
@@ -320,7 +325,6 @@ _read_internal :: proc(f: ^File_Impl, p: []byte) -> (n: i64, err: Error) {
 
 	single_read_length: win32.DWORD
 	total_read: int
-	length := len(p)
 
 	sync.shared_guard(&f.rw_mutex) // multiple readers
 

core/os/stream.odin

@@ -21,6 +21,9 @@ _file_stream_proc :: proc(stream_data: rawptr, mode: io.Stream_Mode, p: []byte,
 	case .Flush:
 		os_err = flush(fd)
 	case .Read:
+		if len(p) == 0 {
+			return 0, nil
+		}
 		n_int, os_err = read(fd, p)
 		n = i64(n_int)
 		if n == 0 && os_err == nil {
@@ -28,18 +31,27 @@ _file_stream_proc :: proc(stream_data: rawptr, mode: io.Stream_Mode, p: []byte,
 		}
 
 	case .Read_At:
+		if len(p) == 0 {
+			return 0, nil
+		}
 		n_int, os_err = read_at(fd, p, offset)
 		n = i64(n_int)
 		if n == 0 && os_err == nil {
 			err = .EOF
 		}
 	case .Write:
+		if len(p) == 0 {
+			return 0, nil
+		}
 		n_int, os_err = write(fd, p)
 		n = i64(n_int)
 		if n == 0 && os_err == nil {
 			err = .EOF
 		}
 	case .Write_At:
+		if len(p) == 0 {
+			return 0, nil
+		}
 		n_int, os_err = write_at(fd, p, offset)
 		n = i64(n_int)
 		if n == 0 && os_err == nil {