Set palette correctly when DVD menu highlight changes to ensure highl…

…ights are the right colour/have the correct transparency.

Fixes #11265

Signed-off-by: Stuart Morgan <smorgan@mythtv.org>

mythtv/libs/libmythtv/DVD/dvdringbuffer.cpp

@@ -1483,6 +1483,14 @@ bool DVDRingBuffer::DVDButtonUpdate(bool b_mode)
         m_button_color[i] = 0xf & (hl.palette >> (16+4 *i ));
     }
 
+    // If the button overlay has already been decoded, make sure
+    // the correct palette for the current highlight is set
+    if (m_dvdMenuButton.rects && (m_dvdMenuButton.num_rects > 1))
+    {
+        guess_palette((uint32_t*)m_dvdMenuButton.rects[1]->pict.data[1],
+                    m_button_color, m_button_alpha);
+    }
+
     m_hl_button.setCoords(hl.sx, hl.sy, hl.ex, hl.ey);
 
     if (((hl.sx + hl.sy) > 0) &&