From 5db5fb7e0ccbae9984632cc11b56347d6462ddcf Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Luis=20=C3=81ngel=20San=20Mart=C3=ADn?=
 <luisangelsm@gmail.com>
Date: Sun, 2 Jun 2019 09:28:54 +0200
Subject: [PATCH] Fix crash when closing YACReader with an empty go to flow gl

---
 common/gl/yacreader_flow_gl.cpp | 22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/common/gl/yacreader_flow_gl.cpp b/common/gl/yacreader_flow_gl.cpp
index 6a094663..4a7b94d5 100644
--- a/common/gl/yacreader_flow_gl.cpp
+++ b/common/gl/yacreader_flow_gl.cpp
@@ -1270,16 +1270,22 @@ YACReaderPageFlowGL::~YACReaderPageFlowGL()
 
     makeCurrent();
 
-    for(auto image : images) {
-        if (image.texture != defaultTexture) {
-            image.texture->destroy();
-            delete image.texture;
+    if (this->context() != nullptr && this->context()->isValid()) {
+        for (auto image : images) {
+            if (image.texture != defaultTexture) {
+                if (image.texture->isCreated()) {
+                    image.texture->destroy();
+                }
+                delete image.texture;
+            }
         }
-    }
 
-    if (defaultTexture != nullptr) {
-        defaultTexture->destroy();
-        delete defaultTexture;
+        if (defaultTexture != nullptr) {
+            if (defaultTexture->isCreated()) {
+                defaultTexture->destroy();
+            }
+            delete defaultTexture;
+        }
     }
 
     doneCurrent();