Fix a problem that JP2 image is not displayed because index color space is used

There are two issues in this bug.

One is that JP2 image is not displayed because it aborts loading Jpx bitmap when the number of components in color space is different with that one in JPX images. I found that the number of components in color space isn't updated after it's initialized. For index color space, the component shall inherit from its base color space.

The second issue is that displayed color is not correct after I fixed the first issue. The root cause is that sRGB is used in JPX image, it doesn't need to map from index to RGB again.

BUG=464215
R=tsepez@chromium.org

Review URL: https://codereview.chromium.org/1009513003

2 files changed, 26 insertions, 13 deletions

diff --git a/core/src/fpdfapi/fpdf_page/fpdf_page_colors.cpp b/core/src/fpdfapi/fpdf_page/fpdf_page_colors.cpp
index 86db177ad7..90895cd966 100644
--- a/core/src/fpdfapi/fpdf_page/fpdf_page_colors.cpp
+++ b/core/src/fpdfapi/fpdf_page/fpdf_page_colors.cpp
@@ -7,6 +7,7 @@
 #include "../../../include/fpdfapi/fpdf_page.h"
 #include "../../../include/fpdfapi/fpdf_module.h"
 #include "../../../include/fxcodec/fx_codec.h"
+#include "../../fxcrt/fx_safe_types.h"
 #include "pageint.h"
 #include <limits.h>
 void sRGB_to_AdobeCMYK(FX_FLOAT R, FX_FLOAT G, FX_FLOAT B, FX_FLOAT& c, FX_FLOAT& m, FX_FLOAT& y, FX_FLOAT& k)
@@ -801,6 +802,7 @@ FX_BOOL CPDF_IndexedCS::v_Load(CPDF_Document* pDoc, CPDF_Array* pArray)
     }
     m_pCountedBaseCS = pDocPageData->FindColorSpacePtr(m_pBaseCS->GetArray());
     m_nBaseComponents = m_pBaseCS->CountComponents();
+    m_nComponents = m_nBaseComponents;
     m_pCompMinMax = FX_Alloc(FX_FLOAT, m_nBaseComponents * 2);
     FX_FLOAT defvalue;
     for (int i = 0; i < m_nBaseComponents; i ++) {
@@ -823,22 +825,29 @@ FX_BOOL CPDF_IndexedCS::v_Load(CPDF_Document* pDoc, CPDF_Array* pArray)
 }
 FX_BOOL CPDF_IndexedCS::GetRGB(FX_FLOAT* pBuf, FX_FLOAT& R, FX_FLOAT& G, FX_FLOAT& B) const
 {
-    int index = (FX_INT32)(*pBuf);
-    if (index < 0 || index > m_MaxIndex) {
+    int index = static_cast<FX_INT32>(*pBuf);
+    if (index < 0 || index > m_MaxIndex || m_nBaseComponents < 1) {
         return FALSE;
     }
-    if (m_nBaseComponents) {
-        if (index == INT_MAX || (index + 1) > INT_MAX / m_nBaseComponents ||
-                (index + 1)*m_nBaseComponents > (int)m_Table.GetLength()) {
-            R = G = B = 0;
-            return FALSE;
-        }
+    FX_SAFE_INT32 colIndex = index;
+    colIndex *= m_nBaseComponents;
+    colIndex += m_nBaseComponents - 1; 
+    if (!colIndex.IsValid() || colIndex.ValueOrDie() >= m_Table.GetLength()) {
+        R = G = B = 0;
+        return FALSE;
     }
+
     CFX_FixedBufGrow<FX_FLOAT, 16> Comps(m_nBaseComponents);
     FX_FLOAT* comps = Comps;
-    FX_LPCBYTE pTable = m_Table;
-    for (int i = 0; i < m_nBaseComponents; i ++) {
-        comps[i] = m_pCompMinMax[i * 2] + m_pCompMinMax[i * 2 + 1] * pTable[index * m_nBaseComponents + i] / 255;
+    if (m_pBaseCS->sRGB()) {
+        for (int i = 0; i < m_nBaseComponents; i ++) {
+            comps[i] = pBuf[i] / 255;
+        }
+    } else {
+        FX_LPCBYTE pTable = m_Table;
+        for (int i = 0; i < m_nBaseComponents; i ++) {
+            comps[i] = m_pCompMinMax[i * 2] + m_pCompMinMax[i * 2 + 1] * pTable[index * m_nBaseComponents + i] / 255;
+        }
     }
     m_pBaseCS->GetRGB(comps, R, G, B);
     return TRUE;
diff --git a/core/src/fpdfapi/fpdf_render/fpdf_render_loadimage.cpp b/core/src/fpdfapi/fpdf_render/fpdf_render_loadimage.cpp
index 79d73518a1..4ed17cdfe5 100644
--- a/core/src/fpdfapi/fpdf_render/fpdf_render_loadimage.cpp
+++ b/core/src/fpdfapi/fpdf_render/fpdf_render_loadimage.cpp
@@ -505,10 +505,14 @@ DIB_COMP_DATA* CPDF_DIBSource::GetDecodeAndMaskArray(FX_BOOL& bDefaultDecode, FX
     }
     int max_data = (1 << m_bpc) - 1;
     CPDF_Array* pDecode = m_pDict->GetArray(FX_BSTRC("Decode"));
+    FX_DWORD arrSize = pDecode ? pDecode->GetCount() : 0;
+    if (arrSize == 0) {
+        return NULL;
+    }
     if (pDecode) {
         for (FX_DWORD i = 0; i < m_nComponents; i ++) {
-            pCompData[i].m_DecodeMin = pDecode->GetNumber(i * 2);
-            FX_FLOAT max = pDecode->GetNumber(i * 2 + 1);
+            pCompData[i].m_DecodeMin = pDecode->GetNumber((i * 2) % arrSize);
+            FX_FLOAT max = pDecode->GetNumber((i * 2 + 1) % arrSize);
             pCompData[i].m_DecodeStep = (max - pCompData[i].m_DecodeMin) / max_data;
             FX_FLOAT def_value, def_min, def_max;
             m_pColorSpace->GetDefaultValue(i, def_value, def_min, def_max);