From c8ca1df2cba490de35549a0f069c1e7e773cbf61 Mon Sep 17 00:00:00 2001
From: Vadim Zeitlin <vadim@wxwidgets.org>
Date: Tue, 1 Oct 2019 01:23:10 +0200
Subject: [PATCH] Don't clear background with transparent brush in wxGCDC

Bail out immediately if the background brush is transparent, for
consistency with the other wxDC implementations.

See #10273.
---
 src/common/dcgraph.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/common/dcgraph.cpp b/src/common/dcgraph.cpp
index 8fb3b5a73d..dc6d018fb2 100644
--- a/src/common/dcgraph.cpp
+++ b/src/common/dcgraph.cpp
@@ -1284,6 +1284,9 @@ void wxGCDCImpl::Clear(void)
 {
     wxCHECK_RET( IsOk(), wxT("wxGCDC(cg)::Clear - invalid DC") );
 
+    if ( m_backgroundBrush.IsTransparent() )
+        return;
+
     if ( m_backgroundBrush.IsOk() )
     {
         m_graphicContext->SetBrush( m_backgroundBrush );