Relax checks added in commit 8f3a311.

core/fpdfapi/fpdf_page/cpdf_meshstream.cpp

Index: core/fpdfapi/fpdf_page/cpdf_meshstream.cpp
diff --git a/core/fpdfapi/fpdf_page/cpdf_meshstream.cpp b/core/fpdfapi/fpdf_page/cpdf_meshstream.cpp
index d3649a1fdce6656521ab5b0375f7a1d137ed8e1b..d0cfc14144cb70bacc98e999df6b6779cce5fce2 100644
--- a/core/fpdfapi/fpdf_page/cpdf_meshstream.cpp
+++ b/core/fpdfapi/fpdf_page/cpdf_meshstream.cpp
@@ -13,6 +13,19 @@
 namespace {
 
 // See PDF Reference 1.7, page 315, table 4.32. (Also table 4.33 and 4.34)
+bool ShouldCheckBPC(ShadingType type) {
+  switch (type) {
+    case kFreeFormGouraudTriangleMeshShading:
+    case kLatticeFormGouraudTriangleMeshShading:
+    case kCoonsPatchMeshShading:
+    case kTensorProductPatchMeshShading:
+      return true;
+    default:
+      return false;
+  }
+}
+
+// Same references as ShouldCheckBPC() above.
 bool IsValidBitsPerComponent(uint32_t x) {
   switch (x) {
     case 1:
@@ -27,7 +40,7 @@ bool IsValidBitsPerComponent(uint32_t x) {
   }
 }
 
-// Same references as IsValidBitsPerComponent() above.
+// Same references as ShouldCheckBPC() above.
 bool IsValidBitsPerCoordinate(uint32_t x) {
   switch (x) {
     case 1:
@@ -78,31 +91,43 @@ CPDF_MeshStream::CPDF_MeshStream(
     : m_type(type),
       m_funcs(funcs),
       m_pShadingStream(pShadingStream),
-      m_pCS(pCS) {}
+      m_pCS(pCS),
+      m_nCoordBits(0),
+      m_nCompBits(0),
+      m_nFlagBits(0),
+      m_nComps(0),
+      m_CoordMax(0),
+      m_CompMax(0),
+      m_xmin(0),
+      m_xmax(0),
+      m_ymin(0),
+      m_ymax(0) {
+  memset(&m_ColorMin, 0, sizeof(m_ColorMin));
+  memset(&m_ColorMax, 0, sizeof(m_ColorMax));
+}
 
 bool CPDF_MeshStream::Load() {
   m_Stream.LoadAllData(m_pShadingStream);
   m_BitStream.Init(m_Stream.GetData(), m_Stream.GetSize());
   CPDF_Dictionary* pDict = m_pShadingStream->GetDict();
   m_nCoordBits = pDict->GetIntegerBy("BitsPerCoordinate");
-  if (!IsValidBitsPerCoordinate(m_nCoordBits))
-    return false;
-
   m_nCompBits = pDict->GetIntegerBy("BitsPerComponent");
-  if (!IsValidBitsPerComponent(m_nCompBits))
-    return false;
+  if (ShouldCheckBPC(m_type)) {
+    if (!IsValidBitsPerCoordinate(m_nCoordBits))
+      return false;
+    if (!IsValidBitsPerComponent(m_nCompBits))
+      return false;
+  }
 
   m_nFlagBits = pDict->GetIntegerBy("BitsPerFlag");
   if (ShouldCheckBitsPerFlag(m_type) && !IsValidBitsPerFlag(m_nFlagBits))
     return false;
 
   uint32_t nComps = m_pCS->CountComponents();
-  if (nComps > 8)
+  if (nComps > kMaxComps)
     return false;
 
   m_nComps = m_funcs.empty() ? nComps : 1;
-  m_CoordMax = m_nCoordBits == 32 ? -1 : (1 << m_nCoordBits) - 1;
-  m_CompMax = (1 << m_nCompBits) - 1;
   CPDF_Array* pDecode = pDict->GetArrayBy("Decode");
   if (!pDecode || pDecode->GetCount() != 4 + m_nComps * 2)
     return false;
@@ -115,6 +140,11 @@ bool CPDF_MeshStream::Load() {
     m_ColorMin[i] = pDecode->GetNumberAt(i * 2 + 4);
     m_ColorMax[i] = pDecode->GetNumberAt(i * 2 + 5);
   }
+
+  if (ShouldCheckBPC(m_type)) {
+    m_CoordMax = m_nCoordBits == 32 ? -1 : (1 << m_nCoordBits) - 1;
+    m_CompMax = (1 << m_nCompBits) - 1;
+  }
   return true;
 }
 
@@ -124,6 +154,7 @@ uint32_t CPDF_MeshStream::GetFlag() {
 }
 
 void CPDF_MeshStream::GetCoords(FX_FLOAT& x, FX_FLOAT& y) {
+  ASSERT(ShouldCheckBPC(m_type));
   if (m_nCoordBits == 32) {
     x = m_xmin + (FX_FLOAT)(m_BitStream.GetBits(m_nCoordBits) *
                             (m_xmax - m_xmin) / (double)m_CoordMax);
@@ -138,7 +169,8 @@ void CPDF_MeshStream::GetCoords(FX_FLOAT& x, FX_FLOAT& y) {
 }
 
 void CPDF_MeshStream::GetColor(FX_FLOAT& r, FX_FLOAT& g, FX_FLOAT& b) {
-  FX_FLOAT color_value[kMaxResults];
+  ASSERT(ShouldCheckBPC(m_type));
+  FX_FLOAT color_value[kMaxComps];
   for (uint32_t i = 0; i < m_nComps; ++i) {
     color_value[i] = m_ColorMin[i] +
                      m_BitStream.GetBits(m_nCompBits) *
@@ -149,11 +181,11 @@ void CPDF_MeshStream::GetColor(FX_FLOAT& r, FX_FLOAT& g, FX_FLOAT& b) {
     return;
   }
 
-  FX_FLOAT result[kMaxResults];
+  FX_FLOAT result[kMaxComps];
   FXSYS_memset(result, 0, sizeof(result));
   int nResults;
   for (const auto& func : m_funcs) {
-    if (func && func->CountOutputs() <= kMaxResults)
+    if (func && func->CountOutputs() <= kMaxComps)
       func->Call(color_value, 1, result, nResults);
   }
   m_pCS->GetRGB(result, r, g, b);