brad/2744 handle shader errors (#3105)

* Partial solution to secondlife/viewer#2744 crash with better error handling.

Handles shader compile errors better, and should turn crash into an LL_ERRS assertion failure.
Strengthed more assertions and improved shader error line numbers

* Even more error handling to get a handle on crash secondlife/viewer#2744
* Improved GLSL correctness on Intel chips that lack OpenGL 4.6 support. secondlife/viewer#2744
* Removed non-working fallback code for gDeferredPostProgram
* Fixed incorrect llmax call

1 files changed, 4 insertions, 1 deletions

diff --git a/indra/llrender/llglslshader.cpp b/indra/llrender/llglslshader.cpp
index 6ba5463acd..45bb24a5b7 100644
--- a/indra/llrender/llglslshader.cpp
+++ b/indra/llrender/llglslshader.cpp
@@ -1046,7 +1046,7 @@ void LLGLSLShader::bind()
 {
     LL_PROFILE_ZONE_SCOPED_CATEGORY_SHADER;
 
-    llassert(mProgramObject != 0);
+    llassert_always(mProgramObject != 0);
 
     gGL.flush();
 
@@ -1069,6 +1069,9 @@ void LLGLSLShader::bind()
         LLShaderMgr::instance()->updateShaderUniforms(this);
         mUniformsDirty = false;
     }
+
+    llassert_always(sCurBoundShaderPtr != nullptr);
+    llassert_always(sCurBoundShader == mProgramObject);
 }
 
 void LLGLSLShader::bind(U8 variant)