From 1b4ffdfbe95f4dc72eb4d0d822e2171fd2195205 Mon Sep 17 00:00:00 2001
From: David Capello <davidcapello@gmail.com>
Date: Mon, 3 Jul 2017 19:49:13 -0300
Subject: [PATCH] Fix glitch rendering background with colors w/alpha = 0

---
 src/render/render.cpp | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/src/render/render.cpp b/src/render/render.cpp
index 316e4e589..7d08b0dd4 100644
--- a/src/render/render.cpp
+++ b/src/render/render.cpp
@@ -855,6 +855,18 @@ void Render::renderBackground(
 
   gfx::Rect dstBounds = area.dstBounds();
 
+  // Fix background color (make them opaque)
+  switch (image->pixelFormat()) {
+    case IMAGE_RGB:
+      m_bgColor1 |= doc::rgba_a_mask;
+      m_bgColor2 |= doc::rgba_a_mask;
+      break;
+    case IMAGE_GRAYSCALE:
+      m_bgColor1 |= doc::graya_a_mask;
+      m_bgColor2 |= doc::graya_a_mask;
+      break;
+  }
+
   // Draw checked background (tile by tile)
   int u_start = u;
   for (y=y_start-tile_h; y<image->height()+tile_h; y+=tile_h) {