SDL: wayland: Fall back to clipboard source data if offer came up empty

SDL Commits
1 
From cf124963116c016df131faa89f32d6565c08a326 Mon Sep 17 00:00:00 2001
From: Ethan Lee <[EMAIL REDACTED]>
Date: Thu, 8 Apr 2021 15:29:54 -0400
Subject: [PATCH] wayland: Fall back to clipboard source data if offer came up
 empty

---
 src/video/wayland/SDL_waylandclipboard.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/video/wayland/SDL_waylandclipboard.c b/src/video/wayland/SDL_waylandclipboard.c
index a94413970..789273b53 100644
--- a/src/video/wayland/SDL_waylandclipboard.c
+++ b/src/video/wayland/SDL_waylandclipboard.c
@@ -80,7 +80,8 @@ Wayland_GetClipboardText(_THIS)
                 if (length > 0) {
                     text = (char*) buffer;
                 }
-            } else if (data_device->selection_source != NULL) {
+            }
+            if (length == 0 && data_device->selection_source != NULL) {
                 buffer = Wayland_data_source_get_data(data_device->selection_source,
                                                       &length, TEXT_MIME, SDL_TRUE);
                 if (length > 0) {