Revert "Make m_pShadingObj a CPDF_Stream instead of CPDF_Object."

There appear to be a bunch of corpus tests which fail with this change such
as FAILURE: shading1.pdf

This reverts commit 85361b227ad6786d2aeef8409b79a8d077a26ee9.

Make m_pShadingObj a CPDF_Stream instead of CPDF_Object.

This object is required to be a stream and was being converted as such. With
the new type checking this caused us to pass a nullptr where previously we'd
have, incorrectly, cast a CPDF_Dictionary to a CPDF_Stream.

This CL changes the m_pShadingObj to always be a CPDF_Stream. Then, we never
go down the bad code path because we check if m_pShadingObj is nullptr earlier
and bail out.

BUG=chromium:547706
TBR=tsepez@chromium.org

Review URL: https://codereview.chromium.org/1414283003 .

5 files changed, 15 insertions, 28 deletions

diff --git a/core/include/fpdfapi/fpdf_resource.h b/core/include/fpdfapi/fpdf_resource.h
index 0b85333cfc..9fe6e2b95f 100644
--- a/core/include/fpdfapi/fpdf_resource.h
+++ b/core/include/fpdfapi/fpdf_resource.h
@@ -688,7 +688,7 @@ class CPDF_ShadingPattern : public CPDF_Pattern {
 
   ~CPDF_ShadingPattern() override;
 
-  CPDF_Stream* m_pShadingObj;
+  CPDF_Object* m_pShadingObj;
 
   FX_BOOL m_bShadingObj;
 
diff --git a/core/src/fpdfapi/fpdf_page/fpdf_page_parser.cpp b/core/src/fpdfapi/fpdf_page/fpdf_page_parser.cpp
index bd4319df11..b12a65a844 100644
--- a/core/src/fpdfapi/fpdf_page/fpdf_page_parser.cpp
+++ b/core/src/fpdfapi/fpdf_page/fpdf_page_parser.cpp
@@ -1128,9 +1128,10 @@ void CPDF_StreamContentParser::Handle_ShadeFill() {
     bbox = m_BBox;
   }
   if (pShading->m_ShadingType >= 4) {
-    bbox.Intersect(_GetShadingBBox(
-        pShading->m_pShadingObj, pShading->m_ShadingType, &pObj->m_Matrix,
-        pShading->m_pFunctions, pShading->m_nFuncs, pShading->m_pCS));
+    bbox.Intersect(_GetShadingBBox(ToStream(pShading->m_pShadingObj),
+                                   pShading->m_ShadingType, &pObj->m_Matrix,
+                                   pShading->m_pFunctions, pShading->m_nFuncs,
+                                   pShading->m_pCS));
   }
   pObj->m_Left = bbox.left;
   pObj->m_Right = bbox.right;
diff --git a/core/src/fpdfapi/fpdf_page/fpdf_page_pattern.cpp b/core/src/fpdfapi/fpdf_page/fpdf_page_pattern.cpp
index d06f481138..7b04d8cd33 100644
--- a/core/src/fpdfapi/fpdf_page/fpdf_page_pattern.cpp
+++ b/core/src/fpdfapi/fpdf_page/fpdf_page_pattern.cpp
@@ -71,12 +71,12 @@ CPDF_ShadingPattern::CPDF_ShadingPattern(CPDF_Document* pDoc,
     CPDF_Dictionary* pDict = m_pPatternObj->GetDict();
     ASSERT(pDict != NULL);
     m_Pattern2Form = pDict->GetMatrix(FX_BSTRC("Matrix"));
-    m_pShadingObj = ToStream(pDict->GetElementValue(FX_BSTRC("Shading")));
+    m_pShadingObj = pDict->GetElementValue(FX_BSTRC("Shading"));
     if (parentMatrix) {
       m_Pattern2Form.Concat(*parentMatrix);
     }
   } else {
-    m_pShadingObj = ToStream(pPatternObj);
+    m_pShadingObj = pPatternObj;
   }
   m_ShadingType = 0;
   m_pCS = NULL;
diff --git a/core/src/fpdfapi/fpdf_render/fpdf_render_pattern.cpp b/core/src/fpdfapi/fpdf_render/fpdf_render_pattern.cpp
index 015f1a3166..4ed6c07675 100644
--- a/core/src/fpdfapi/fpdf_render/fpdf_render_pattern.cpp
+++ b/core/src/fpdfapi/fpdf_render/fpdf_render_pattern.cpp
@@ -881,18 +881,20 @@ void CPDF_RenderStatus::DrawShading(CPDF_ShadingPattern* pPattern,
                         pColorSpace, alpha);
       break;
     case 4: {
-      DrawFreeGouraudShading(pBitmap, &FinalMatrix, pPattern->m_pShadingObj,
-                             pFuncs, nFuncs, pColorSpace, alpha);
+      DrawFreeGouraudShading(pBitmap, &FinalMatrix,
+                             ToStream(pPattern->m_pShadingObj), pFuncs, nFuncs,
+                             pColorSpace, alpha);
     } break;
     case 5: {
-      DrawLatticeGouraudShading(pBitmap, &FinalMatrix, pPattern->m_pShadingObj,
-                                pFuncs, nFuncs, pColorSpace, alpha);
+      DrawLatticeGouraudShading(pBitmap, &FinalMatrix,
+                                ToStream(pPattern->m_pShadingObj), pFuncs,
+                                nFuncs, pColorSpace, alpha);
     } break;
     case 6:
     case 7: {
       DrawCoonPatchMeshes(pPattern->m_ShadingType - 6, pBitmap, &FinalMatrix,
-                          pPattern->m_pShadingObj, pFuncs, nFuncs, pColorSpace,
-                          fill_mode, alpha);
+                          ToStream(pPattern->m_pShadingObj), pFuncs, nFuncs,
+                          pColorSpace, fill_mode, alpha);
     } break;
   }
   if (bAlphaMode) {
diff --git a/core/src/fpdfapi/fpdf_render/fpdf_render_pattern_embeddertest.cpp b/core/src/fpdfapi/fpdf_render/fpdf_render_pattern_embeddertest.cpp
deleted file mode 100644
index 30d7a416be..0000000000
--- a/core/src/fpdfapi/fpdf_render/fpdf_render_pattern_embeddertest.cpp
+++ /dev/null
@@ -1,16 +0,0 @@
-// Copyright 2015 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.
-
-#include "../../../testing/embedder_test.h"
-#include "testing/gtest/include/gtest/gtest.h"
-
-class FPDFRenderPatternEmbeddertest : public EmbedderTest {};
-
-TEST_F(FPDFRenderPatternEmbeddertest, LoadError_547706) {
-  // Test shading where object is a dictionary instead of a stream.
-  EXPECT_TRUE(OpenDocument("testing/resources/bug_547706.pdf"));
-  FPDF_PAGE page = LoadPage(0);
-  RenderPage(page);
-  UnloadPage(page);
-}