Slightly simplify CPDF_Color::SetColorSpace().

All the callers pass in a valid colorspace. SetColorSpace() is the only
caller to CPDF_ColorSpace::GetDefaultColor(). Also adjust that method to
make it harder to use incorrectly.

Change-Id: I5cf7b6d2abef630e1b9443043b13d1c2b5bed18a
Reviewed-on: https://pdfium-review.googlesource.com/30351
Reviewed-by: Henrique Nakashima <hnakashima@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>

3 files changed, 17 insertions, 13 deletions

diff --git a/core/fpdfapi/page/cpdf_color.cpp b/core/fpdfapi/page/cpdf_color.cpp
index d364e8e822..73e3d36ec4 100644
--- a/core/fpdfapi/page/cpdf_color.cpp
+++ b/core/fpdfapi/page/cpdf_color.cpp
@@ -60,6 +60,7 @@ bool CPDF_Color::IsPatternInternal() const {
 }
 
 void CPDF_Color::SetColorSpace(CPDF_ColorSpace* pCS) {
+  ASSERT(pCS);
   if (m_pCS == pCS) {
     if (!m_pBuffer)
       m_pBuffer = pCS->CreateBuf();
@@ -72,10 +73,10 @@ void CPDF_Color::SetColorSpace(CPDF_ColorSpace* pCS) {
   ReleaseColorSpace();
 
   m_pCS = pCS;
-  if (pCS) {
+  if (IsPatternInternal())
     m_pBuffer = pCS->CreateBuf();
-    pCS->GetDefaultColor(m_pBuffer);
-  }
+  else
+    m_pBuffer = pCS->CreateBufAndSetDefaultColor();
 }
 
 void CPDF_Color::SetValue(const float* comps) {
diff --git a/core/fpdfapi/page/cpdf_colorspace.cpp b/core/fpdfapi/page/cpdf_colorspace.cpp
index 7cecb19188..d9717f1d58 100644
--- a/core/fpdfapi/page/cpdf_colorspace.cpp
+++ b/core/fpdfapi/page/cpdf_colorspace.cpp
@@ -485,25 +485,25 @@ void CPDF_ColorSpace::Release() {
   delete this;
 }
 
-int CPDF_ColorSpace::GetBufSize() const {
+size_t CPDF_ColorSpace::GetBufSize() const {
   if (m_Family == PDFCS_PATTERN)
     return sizeof(PatternValue);
   return m_nComponents * sizeof(float);
 }
 
-float* CPDF_ColorSpace::CreateBuf() {
-  int size = GetBufSize();
-  return reinterpret_cast<float*>(FX_Alloc(uint8_t, size));
+float* CPDF_ColorSpace::CreateBuf() const {
+  return reinterpret_cast<float*>(FX_Alloc(uint8_t, GetBufSize()));
 }
 
-void CPDF_ColorSpace::GetDefaultColor(float* buf) const {
-  if (!buf || m_Family == PDFCS_PATTERN)
-    return;
+float* CPDF_ColorSpace::CreateBufAndSetDefaultColor() const {
+  ASSERT(m_Family != PDFCS_PATTERN);
 
+  float* buf = CreateBuf();
   float min;
   float max;
   for (uint32_t i = 0; i < m_nComponents; i++)
     GetDefaultValue(i, &buf[i], &min, &max);
+  return buf;
 }
 
 uint32_t CPDF_ColorSpace::CountComponents() const {
diff --git a/core/fpdfapi/page/cpdf_colorspace.h b/core/fpdfapi/page/cpdf_colorspace.h
index e9108578f5..b9879d135c 100644
--- a/core/fpdfapi/page/cpdf_colorspace.h
+++ b/core/fpdfapi/page/cpdf_colorspace.h
@@ -53,9 +53,12 @@ class CPDF_ColorSpace {
 
   void Release();
 
-  int GetBufSize() const;
-  float* CreateBuf();
-  void GetDefaultColor(float* buf) const;
+  size_t GetBufSize() const;
+  float* CreateBuf() const;
+
+  // Should only be called if this colorspace is not a pattern.
+  float* CreateBufAndSetDefaultColor() const;
+
   uint32_t CountComponents() const;
   int GetFamily() const { return m_Family; }
   bool IsSpecial() const {