Only call shading code with streams.

core/fpdfapi/fpdf_render/fpdf_render_pattern.cpp

Index: core/fpdfapi/fpdf_render/fpdf_render_pattern.cpp
diff --git a/core/fpdfapi/fpdf_render/fpdf_render_pattern.cpp b/core/fpdfapi/fpdf_render/fpdf_render_pattern.cpp
index 6ac380e43a3890f8a8d1e8ebad3b31bf709b4588..aa7abfd873025a32a8deb7a5006750ef655136bd 100644
--- a/core/fpdfapi/fpdf_render/fpdf_render_pattern.cpp
+++ b/core/fpdfapi/fpdf_render/fpdf_render_pattern.cpp
@@ -889,21 +889,33 @@ void CPDF_RenderStatus::DrawShading(CPDF_ShadingPattern* pPattern,
                         pColorSpace, alpha);
       break;
     case kFreeFormGouraudTriangleMeshShading: {
-      DrawFreeGouraudShading(pBitmap, &FinalMatrix,
-                             ToStream(pPattern->m_pShadingObj), pFuncs, nFuncs,
-                             pColorSpace, alpha);
+      // The shading object can be a stream or a dictionary. We do not handle
+      // the case of dictionary at the moment.
+      if (pPattern->m_pShadingObj->IsStream()) {

[Tom Sepez, 2016/04/21 16:24:24]

nit: maybe if (CPFD_Stream* pStream = pPattern->m_pShadingObj->AsStream()) {

[dsinclair, 2016/04/21 16:56:00]

Done.

+        DrawFreeGouraudShading(pBitmap, &FinalMatrix,
+                               ToStream(pPattern->m_pShadingObj), pFuncs,

[Tom Sepez, 2016/04/21 16:24:24]

nit: then you can write
  pStream, pFuncts, 

and save the redundant virtual calls.

[dsinclair, 2016/04/21 16:56:00]

Done.

+                               nFuncs, pColorSpace, alpha);
+      }
     } break;
     case kLatticeFormGouraudTriangleMeshShading: {
-      DrawLatticeGouraudShading(pBitmap, &FinalMatrix,
-                                ToStream(pPattern->m_pShadingObj), pFuncs,
-                                nFuncs, pColorSpace, alpha);
+      // The shading object can be a stream or a dictionary. We do not handle
+      // the case of dictionary at the moment.
+      if (pPattern->m_pShadingObj->IsStream()) {
+        DrawLatticeGouraudShading(pBitmap, &FinalMatrix,
+                                  ToStream(pPattern->m_pShadingObj), pFuncs,
+                                  nFuncs, pColorSpace, alpha);
+      }
     } break;
     case kCoonsPatchMeshShading:
     case kTensorProductPatchMeshShading: {
-      DrawCoonPatchMeshes(
-          pPattern->m_ShadingType == kTensorProductPatchMeshShading, pBitmap,
-          &FinalMatrix, ToStream(pPattern->m_pShadingObj), pFuncs, nFuncs,
-          pColorSpace, fill_mode, alpha);
+      // The shading object can be a stream or a dictionary. We do not handle
+      // the case of dictionary at the moment.
+      if (pPattern->m_pShadingObj->IsStream()) {
+        DrawCoonPatchMeshes(
+            pPattern->m_ShadingType == kTensorProductPatchMeshShading, pBitmap,
+            &FinalMatrix, ToStream(pPattern->m_pShadingObj), pFuncs, nFuncs,
+            pColorSpace, fill_mode, alpha);
+      }
     } break;
   }
   if (bAlphaMode) {