commit a49689f3dde65ec07be0aa09078089d813e427f3
author Tom Sepez <tsepez@chromium.org> Fri Jan 18 20:58:06 2019 +0000
committer Chromium commit bot <commit-bot@chromium.org> Fri Jan 18 20:58:06 2019 +0000
tree 7897067ead87e8cb2b0f9a2d87bd2802a11a452f
parent 7429e33b521c614fc6587f8805c7bed83f99b18c

Remove ~4KB worth of unused zeros from cxfa_graphics.cpp.

Return valid reference for out-of-bounds indices as a
defensive measure until we can be sure that this can't happen.

Change-Id: Ibc54f0c9e0cd30bf4fd6bc374866bca07520647a
Reviewed-on: https://pdfium-review.googlesource.com/c/48511
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>

xfa/fxgraphics/cxfa_graphics.cpp

diff --git a/xfa/fxgraphics/cxfa_graphics.cpp b/xfa/fxgraphics/cxfa_graphics.cpp
index 3249927..5e4c556 100644
--- a/xfa/fxgraphics/cxfa_graphics.cpp
+++ b/xfa/fxgraphics/cxfa_graphics.cpp
@@ -25,15 +25,13 @@
   FX_CONTEXT_Device,
 };
 
-#define FX_HATCHSTYLE_Total 53
-
 struct FX_HATCHDATA {
   int32_t width;
   int32_t height;
   uint8_t maskBits[64];
 };
 
-const FX_HATCHDATA hatchBitmapData[FX_HATCHSTYLE_Total] = {
+const FX_HATCHDATA kHatchBitmapData[] = {
     {16,  // Horizontal
      16,
      {
@@ -96,6 +94,23 @@
      }},
 };
 
+const FX_HATCHDATA kHatchPlaceHolder = {
+    0,
+    0,
+    {
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    }};
+
+const FX_HATCHDATA& GetHatchBitmapData(size_t index) {
+  return index < FX_ArraySize(kHatchBitmapData) ? kHatchBitmapData[index]
+                                                : kHatchPlaceHolder;
+}
+
 }  // namespace
 
 CXFA_Graphics::CXFA_Graphics(CFX_RenderDevice* renderDevice)
@@ -273,7 +288,8 @@
   m_renderDevice->GetDIBits(bmp, 0, 0);
 
   FX_HatchStyle hatchStyle = m_info.fillColor.GetPattern()->m_hatchStyle;
-  const FX_HATCHDATA& data = hatchBitmapData[static_cast<int>(hatchStyle)];
+  const FX_HATCHDATA& data =
+      GetHatchBitmapData(static_cast<size_t>(hatchStyle));
 
   auto mask = pdfium::MakeRetain<CFX_DIBitmap>();
   mask->Create(data.width, data.height, FXDIB_1bppMask);