Handle more stream errors on os Darwin

core/os/os_darwin.odin

@@ -728,7 +728,12 @@ write :: proc(fd: Handle, data: []byte) -> (int, Error) {
 
 	bytes_written := _unix_write(fd, raw_data(data), to_write)
 	if bytes_written < 0 {
-		return -1, get_last_error()
+		errno := get_last_error()
+		switch errno {
+		case .EBADF:
+			return 0, .Invalid_Stream
+		}
+		return 0, errno
 	}
 	return bytes_written, nil
 }
@@ -742,7 +747,12 @@ read :: proc(fd: Handle, data: []u8) -> (int, Error) {
 
 	bytes_read := _unix_read(fd, raw_data(data), to_read)
 	if bytes_read < 0 {
-		return -1, get_last_error()
+		errno := get_last_error()
+		switch errno {
+		case .EBADF:
+			return 0, .Invalid_Stream
+		}
+		return 0, errno
 	}
 	return bytes_read, nil
 }
@@ -756,7 +766,12 @@ read_at :: proc(fd: Handle, data: []byte, offset: i64) -> (int, Error) {
 
 	bytes_read := _unix_pread(fd, raw_data(data), to_read, offset)
 	if bytes_read < 0 {
-		return -1, get_last_error()
+		errno := get_last_error()
+		switch errno {
+		case .EBADF:
+			return 0, .Invalid_Stream
+		}
+		return 0, errno
 	}
 	return bytes_read, nil
 }
@@ -770,17 +785,35 @@ write_at :: proc(fd: Handle, data: []byte, offset: i64) -> (int, Error) {
 
 	bytes_written := _unix_pwrite(fd, raw_data(data), to_write, offset)
 	if bytes_written < 0 {
-		return -1, get_last_error()
+		errno := get_last_error()
+		switch errno {
+		case .EBADF:
+			return 0, .Invalid_Stream
+		}
+		return 0, errno
 	}
 	return bytes_written, nil
 }
 
 seek :: proc(fd: Handle, offset: i64, whence: int) -> (i64, Error) {
 	assert(fd != -1)
+	switch whence {
+	case SEEK_SET, SEEK_CUR, SEEK_END:
+		break
+	case:
+		return 0, .Invalid_Whence
+	}
 
 	final_offset := i64(_unix_lseek(fd, int(offset), c.int(whence)))
 	if final_offset == -1 {
-		return 0, get_last_error()
+		errno := get_last_error()
+		switch errno {
+		case .EINVAL:
+			return 0, .Invalid_Offset
+		case .EBADF:
+			return 0, .Invalid_Stream
+		}
+		return 0, errno
 	}
 	return final_offset, nil
 }
@@ -789,6 +822,9 @@ seek :: proc(fd: Handle, offset: i64, whence: int) -> (i64, Error) {
 file_size :: proc(fd: Handle) -> (i64, Error) {
 	prev, _   := seek(fd, 0, SEEK_CUR)
 	size, err := seek(fd, 0, SEEK_END)
+	if err == .EBADF {
+		return 0, .Invalid_Stream
+	}
 	seek(fd, prev, SEEK_SET)
 	return i64(size), err
 }
@@ -1042,7 +1078,17 @@ access :: proc(path: string, mask: int) -> bool {
 }
 
 flush :: proc(fd: Handle) -> Error {
-	return cast(Platform_Error)_unix_fsync(fd)
+	result := _unix_fsync(fd)
+	if result == -1 {
+		errno := get_last_error()
+		switch errno {
+		case .EBADF:
+			return .Invalid_Stream
+		case:
+			return errno
+		}
+	}
+	return nil
 }
 
 @(require_results)