commit 5eda47dd4c3ce95c84188c042cf4823764a3e500
author Lei Zhang <thestig@chromium.org> Mon Nov 14 21:44:34 2022 +0000
committer Pdfium LUCI CQ <pdfium-scoped@luci-project-accounts.iam.gserviceaccount.com> Mon Nov 14 21:44:34 2022 +0000
tree 088be7f664c13b62737debceeb9f4ccc81a3c6da
parent b4b2831a719c39834a0250a0169494cc25472a8f

Remove a check that is always true in CPDF_IndexedCS.

By the time CPDF_IndexedCS::GetRGB() gets called,
CPDF_IndexedCS::v_Load() would have already set `m_nBaseComponents` to a
non-zero value. So there is no need to check if `m_nBaseComponents` is
zero. Add DCHECKs to validate these assumptions instead.

Change-Id: I9893e1e653144180b24cbc31dc0ee90d4f9319f2
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/101251
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>

core/fpdfapi/page/cpdf_indexedcs.cpp

diff --git a/core/fpdfapi/page/cpdf_indexedcs.cpp b/core/fpdfapi/page/cpdf_indexedcs.cpp
index 33a8a1b..32a36bd 100644
--- a/core/fpdfapi/page/cpdf_indexedcs.cpp
+++ b/core/fpdfapi/page/cpdf_indexedcs.cpp
@@ -53,6 +53,7 @@
     return 0;
 
   m_nBaseComponents = m_pBaseCS->CountComponents();
+  DCHECK(m_nBaseComponents);
   m_pCompMinMax = DataVector<float>(Fx2DSizeOrDie(m_nBaseComponents, 2));
   float defvalue;
   for (uint32_t i = 0; i < m_nBaseComponents; i++) {
@@ -84,17 +85,19 @@
   if (index < 0 || index > m_MaxIndex)
     return false;
 
-  if (m_nBaseComponents) {
-    FX_SAFE_SIZE_T length = index;
-    length += 1;
-    length *= m_nBaseComponents;
-    if (!length.IsValid() || length.ValueOrDie() > m_Table.GetLength()) {
-      *R = 0;
-      *G = 0;
-      *B = 0;
-      return false;
-    }
+  DCHECK(m_nBaseComponents);
+  DCHECK_EQ(m_nBaseComponents, m_pBaseCS->CountComponents());
+
+  FX_SAFE_SIZE_T length = index;
+  length += 1;
+  length *= m_nBaseComponents;
+  if (!length.IsValid() || length.ValueOrDie() > m_Table.GetLength()) {
+    *R = 0;
+    *G = 0;
+    *B = 0;
+    return false;
   }
+
   std::vector<float> comps(m_nBaseComponents);
   const uint8_t* pTable = m_Table.raw_str();
   for (uint32_t i = 0; i < m_nBaseComponents; ++i) {
@@ -102,6 +105,5 @@
         m_pCompMinMax[i * 2] +
         m_pCompMinMax[i * 2 + 1] * pTable[index * m_nBaseComponents + i] / 255;
   }
-  DCHECK_EQ(m_nBaseComponents, m_pBaseCS->CountComponents());
   return m_pBaseCS->GetRGB(comps, R, G, B);
 }