2 files changed, 24 insertions, 31 deletions

diff --git a/core/src/fxcodec/jbig2/JBig2_GsidProc.cpp b/core/src/fxcodec/jbig2/JBig2_GsidProc.cpp
index d89bb8f249..5f423c4b04 100644
--- a/core/src/fxcodec/jbig2/JBig2_GsidProc.cpp
+++ b/core/src/fxcodec/jbig2/JBig2_GsidProc.cpp
@@ -11,6 +11,7 @@
 #include "JBig2_BitStream.h"
 #include "JBig2_GrdProc.h"
 #include "JBig2_Image.h"
+#include "JBig2_List.h"
 
 FX_DWORD* CJBig2_GSIDProc::decode_Arith(CJBig2_ArithDecoder* pArithDecoder,
                                         JBig2ArithCtx* gbContext,
@@ -38,47 +39,32 @@ FX_DWORD* CJBig2_GSIDProc::decode_Arith(CJBig2_ArithDecoder* pArithDecoder,
     pGRD->GBAT[7] = -2;
   }
 
-  nonstd::unique_ptr<CJBig2_Image*, FxFreeDeleter> GSPLANES(
-      FX_Alloc(CJBig2_Image*, GSBPP));
-  JBIG2_memset(GSPLANES.get(), 0, sizeof(CJBig2_Image*) * GSBPP);
-  FXCODEC_STATUS status = pGRD->Start_decode_Arith(
-      &GSPLANES.get()[GSBPP - 1], pArithDecoder, gbContext, nullptr);
-  while (status == FXCODEC_STATUS_DECODE_TOBECONTINUE) {
-    pGRD->Continue_decode(pPause);
-  }
-  if (!GSPLANES.get()[GSBPP - 1])
-    return nullptr;
-
-  int32_t J = GSBPP - 2;
-  while (J >= 0) {
-    FXCODEC_STATUS status = pGRD->Start_decode_Arith(
-        &GSPLANES.get()[J], pArithDecoder, gbContext, nullptr);
-    while (status == FXCODEC_STATUS_DECODE_TOBECONTINUE) {
+  CJBig2_List<CJBig2_Image> GSPLANES(GSBPP);
+  for (int32_t i = GSBPP - 1; i >= 0; --i) {
+    CJBig2_Image* pImage = nullptr;
+    FXCODEC_STATUS status =
+        pGRD->Start_decode_Arith(&pImage, pArithDecoder, gbContext, nullptr);
+    while (status == FXCODEC_STATUS_DECODE_TOBECONTINUE)
       pGRD->Continue_decode(pPause);
-    }
-    if (!GSPLANES.get()[J]) {
-      for (int32_t K = GSBPP - 1; K > J; --K) {
-        delete GSPLANES.get()[K];
-        return nullptr;
-      }
-    }
-    GSPLANES.get()[J]->composeFrom(0, 0, GSPLANES.get()[J + 1],
-                                   JBIG2_COMPOSE_XOR);
-    J = J - 1;
+
+    if (!pImage)
+      return nullptr;
+
+    GSPLANES.set(i, pImage);
+
+    if (i < GSBPP - 1)
+      pImage->composeFrom(0, 0, GSPLANES.get(i + 1), JBIG2_COMPOSE_XOR);
   }
   nonstd::unique_ptr<FX_DWORD, FxFreeDeleter> GSVALS(
       FX_Alloc2D(FX_DWORD, GSW, GSH));
   JBIG2_memset(GSVALS.get(), 0, sizeof(FX_DWORD) * GSW * GSH);
   for (FX_DWORD y = 0; y < GSH; ++y) {
     for (FX_DWORD x = 0; x < GSW; ++x) {
-      for (J = 0; J < GSBPP; ++J) {
-        GSVALS.get()[y * GSW + x] |= GSPLANES.get()[J]->getPixel(x, y) << J;
+      for (int32_t i = 0; i < GSBPP; ++i) {
+        GSVALS.get()[y * GSW + x] |= GSPLANES.get(i)->getPixel(x, y) << i;
       }
     }
   }
-  for (J = 0; J < GSBPP; ++J) {
-    delete GSPLANES.get()[J];
-  }
   return GSVALS.release();
 }
 
diff --git a/core/src/fxcodec/jbig2/JBig2_List.h b/core/src/fxcodec/jbig2/JBig2_List.h
index ffdd22c3ca..6097294e17 100644
--- a/core/src/fxcodec/jbig2/JBig2_List.h
+++ b/core/src/fxcodec/jbig2/JBig2_List.h
@@ -15,6 +15,7 @@ template <class TYPE>
 class CJBig2_List {
  public:
   CJBig2_List() {}
+  explicit CJBig2_List(size_t count) { resize(count); }
 
   ~CJBig2_List() {
     clear();
@@ -34,6 +35,12 @@ class CJBig2_List {
   // Takes ownership of |pItem|.
   void push_back(TYPE* pItem) { m_vector.push_back(pItem); }
 
+  // Takes ownership of |pItem|.
+  void set(size_t index, TYPE* pItem) {
+    delete m_vector[index];
+    m_vector[index] = pItem;
+  }
+
   void resize(size_t count) {
     for (size_t i = count; i < size(); ++i)
       delete m_vector[i];