Fix colorspace loading for mutually referencing colorspaces.

For example, Indexed colorspace A uses ICC Based colorspace B as its
"base". B declares A as its "Alternate" fallback.

Bug: chromium:759012
Change-Id: I4b78e68b9a77456050ecae4452837495546bf93d
Reviewed-on: https://pdfium-review.googlesource.com/12471
Commit-Queue: Henrique Nakashima <hnakashima@chromium.org>
Reviewed-by: dsinclair <dsinclair@chromium.org>
Reviewed-by: Ryan Harrison <rharrison@chromium.org>

1 files changed, 10 insertions, 11 deletions

diff --git a/core/fpdfapi/page/cpdf_docpagedata.cpp b/core/fpdfapi/page/cpdf_docpagedata.cpp
index 71143d0b6c..1af9d6ee22 100644
--- a/core/fpdfapi/page/cpdf_docpagedata.cpp
+++ b/core/fpdfapi/page/cpdf_docpagedata.cpp
@@ -212,10 +212,10 @@ CPDF_ColorSpace* CPDF_DocPageData::GetColorSpace(
     CPDF_Object* pCSObj,
     const CPDF_Dictionary* pResources) {
   std::set<CPDF_Object*> visited;
-  return GetColorSpaceImpl(pCSObj, pResources, &visited);
+  return GetColorSpaceGuarded(pCSObj, pResources, &visited);
 }
 
-CPDF_ColorSpace* CPDF_DocPageData::GetColorSpaceImpl(
+CPDF_ColorSpace* CPDF_DocPageData::GetColorSpaceGuarded(
     CPDF_Object* pCSObj,
     const CPDF_Dictionary* pResources,
     std::set<CPDF_Object*>* pVisited) {
@@ -225,15 +225,16 @@ CPDF_ColorSpace* CPDF_DocPageData::GetColorSpaceImpl(
   if (pdfium::ContainsKey(*pVisited, pCSObj))
     return nullptr;
 
+  pdfium::ScopedSetInsertion<CPDF_Object*> insertion(pVisited, pCSObj);
+
   if (pCSObj->IsName()) {
     CFX_ByteString name = pCSObj->GetString();
     CPDF_ColorSpace* pCS = CPDF_ColorSpace::ColorspaceFromName(name);
     if (!pCS && pResources) {
       CPDF_Dictionary* pList = pResources->GetDictFor("ColorSpace");
       if (pList) {
-        pdfium::ScopedSetInsertion<CPDF_Object*> insertion(pVisited, pCSObj);
-        return GetColorSpaceImpl(pList->GetDirectObjectFor(name), nullptr,
-                                 pVisited);
+        return GetColorSpaceGuarded(pList->GetDirectObjectFor(name), nullptr,
+                                    pVisited);
       }
     }
     if (!pCS || !pResources)
@@ -258,8 +259,7 @@ CPDF_ColorSpace* CPDF_DocPageData::GetColorSpaceImpl(
     if (!pDefaultCS)
       return pCS;
 
-    pdfium::ScopedSetInsertion<CPDF_Object*> insertion(pVisited, pCSObj);
-    return GetColorSpaceImpl(pDefaultCS, nullptr, pVisited);
+    return GetColorSpaceGuarded(pDefaultCS, nullptr, pVisited);
   }
 
   CPDF_Array* pArray = pCSObj->AsArray();
@@ -267,9 +267,8 @@ CPDF_ColorSpace* CPDF_DocPageData::GetColorSpaceImpl(
     return nullptr;
 
   if (pArray->GetCount() == 1) {
-    pdfium::ScopedSetInsertion<CPDF_Object*> insertion(pVisited, pCSObj);
-    return GetColorSpaceImpl(pArray->GetDirectObjectAt(0), pResources,
-                             pVisited);
+    return GetColorSpaceGuarded(pArray->GetDirectObjectAt(0), pResources,
+                                pVisited);
   }
 
   CPDF_CountedColorSpace* csData = nullptr;
@@ -282,7 +281,7 @@ CPDF_ColorSpace* CPDF_DocPageData::GetColorSpaceImpl(
   }
 
   std::unique_ptr<CPDF_ColorSpace> pCS =
-      CPDF_ColorSpace::Load(m_pPDFDoc.Get(), pArray);
+      CPDF_ColorSpace::Load(m_pPDFDoc.Get(), pArray, pVisited);
   if (!pCS)
     return nullptr;