Fail to create GrContext when we get a NULL for a GL/GLSL version string

src/gpu/gl/GrGLAssembleInterface.cpp

 
 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "GrGLAssembleInterface.h"
 #include "GrGLUtil.h"
 
 #define GET_PROC(F) functions->f ## F = (GrGL ## F ## Proc) get(ctx, "gl" #F)
 #define GET_PROC_SUFFIX(F, S) functions->f ## F = (GrGL ## F ## Proc) get(ctx, "gl" #F #S)
 #define GET_PROC_LOCAL(F) GrGL ## F ## Proc F = (GrGL ## F ## Proc) get(ctx, "gl" #F)
 
 const GrGLInterface* GrGLAssembleGLInterface(void* ctx, GrGLGetProc get) {
     GET_PROC_LOCAL(GetString);
     GET_PROC_LOCAL(GetStringi);
     GET_PROC_LOCAL(GetIntegerv);
 
     // GetStringi may be NULL depending on the GL version.
     if (NULL == GetString || NULL == GetIntegerv) {
         return NULL;
     }
 
     const char* versionString = (const char*) GetString(GR_GL_VERSION);
     GrGLVersion glVer = GrGLGetVersionFromString(versionString);
 
-    if (glVer < GR_GL_VER(1,5)) {
+    if (glVer < GR_GL_VER(1,5) || GR_GL_INVALID_VER == glVer) {
         // We must have array and element_array buffer objects.
         return NULL;
     }
 
     GrGLExtensions extensions;
     if (!extensions.init(kGL_GrGLStandard, GetString, GetStringi, GetIntegerv)) {
         return NULL;
     }
 
     GrGLInterface* interface = SkNEW(GrGLInterface());
@@ skipping 239 matching lines @@
         GET_PROC(InvalidateSubFramebuffer);
         GET_PROC(InvalidateTexImage);
         GET_PROC(InvalidateTexSubImage);
     }
 
     interface->fStandard = kGL_GrGLStandard;
     interface->fExtensions.swap(&extensions);
 
     return interface;
 }