From 4898a0429d8b34f5e27ea4101bbe23b11f5c33c6 Mon Sep 17 00:00:00 2001
From: Bertrand Songis <bsongis@gmail.com>
Date: Fri, 20 Mar 2020 11:39:58 +0100
Subject: [PATCH] TransparentBufferedWindow fix

---
 radio/src/thirdparty/libopenui/src/bufferedwindow.h | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/radio/src/thirdparty/libopenui/src/bufferedwindow.h b/radio/src/thirdparty/libopenui/src/bufferedwindow.h
index 74aa70e24..6e6aa4a2c 100644
--- a/radio/src/thirdparty/libopenui/src/bufferedwindow.h
+++ b/radio/src/thirdparty/libopenui/src/bufferedwindow.h
@@ -82,8 +82,13 @@ class TransparentBufferedWindow: public BufferedWindow<T>
 
       if (this->paintUpdateNeeded) {
         this->paintUpdate(dc);
-        this->bitmap->drawBitmap(0, 0, dc, dc->getOffsetX(), dc->getOffsetY());
-        this->paintUpdateNeeded = false;
+        // we can only store the bitmap if fully drawn
+        coord_t xmin, xmax, ymin, ymax;
+        dc->getClippingRect(xmin, xmax, ymin, ymax);
+        if (xmax - xmin >= this->width() && ymax - ymin >= this->height()) {
+          this->bitmap->drawBitmap(0, 0, dc, dc->getOffsetX(), dc->getOffsetY());
+          this->paintUpdateNeeded = false;
+        }
       }
       else {
         dc->drawBitmap(0, 0, this->bitmap);