From f25532db78127efd58df34a98d735fc6f9345ad2 Mon Sep 17 00:00:00 2001
From: rdb <git@rdb.name>
Date: Fri, 3 May 2019 20:48:51 +0200
Subject: [PATCH] glgsg: properly handle shader compilation failure

Fixes #645
---
 panda/src/glstuff/glShaderContext_src.cxx | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/panda/src/glstuff/glShaderContext_src.cxx b/panda/src/glstuff/glShaderContext_src.cxx
index 5a7eda65fc..200e39004d 100644
--- a/panda/src/glstuff/glShaderContext_src.cxx
+++ b/panda/src/glstuff/glShaderContext_src.cxx
@@ -3206,6 +3206,10 @@ glsl_compile_and_link() {
     valid &= glsl_compile_shader(Shader::ST_compute);
   }
 
+  if (!valid) {
+    return false;
+  }
+
   // There might be warnings, so report those.  GLSLShaders::const_iterator
   // it; for (it = _glsl_shaders.begin(); it != _glsl_shaders.end(); ++it) {
   // glsl_report_shader_errors(*it); }