Only call shading code with streams.

core/fpdfapi/fpdf_render/fpdf_render_pattern.cpp

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #include "core/fpdfapi/fpdf_render/render_int.h"
 
 #include "core/fpdfapi/fpdf_page/cpdf_graphicstates.h"
 #include "core/fpdfapi/fpdf_page/cpdf_meshstream.h"
@@ skipping 871 matching lines @@
       break;
     case kAxialShading:
       DrawAxialShading(pBitmap, &FinalMatrix, pDict, pFuncs, nFuncs,
                        pColorSpace, alpha);
       break;
     case kRadialShading:
       DrawRadialShading(pBitmap, &FinalMatrix, pDict, pFuncs, nFuncs,
                         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) {
     pBitmap->LoadChannel(FXDIB_Red, pBitmap, FXDIB_Alpha);
   }
   if (m_Options.m_ColorMode == RENDER_COLOR_GRAY) {
     pBitmap->ConvertColorScale(m_Options.m_ForeColor, m_Options.m_BackColor);
   }
   buffer.OutputToDevice();
 }
@@ skipping 293 matching lines @@
     }
   }
   if (bStroke) {
     CPDF_Color& StrokeColor = *pPathObj->m_ColorState.GetStrokeColor();
     if (StrokeColor.m_pCS && StrokeColor.m_pCS->GetFamily() == PDFCS_PATTERN) {
       DrawPathWithPattern(pPathObj, pObj2Device, &StrokeColor, TRUE);
       bStroke = FALSE;
     }
   }
 }