copy graphics state fully

The dash parameters where not copied; the copy
could point at random data and cause corpus
tests to hang when testing Skia.

PDFium measures text directly by calling FreeType.
Turn off hinting altogether in Skia so that drawn
text matches the metrics that PDFium measures.

Premultiply bits retrieved from images, and check
to see that the device bits are always
premultiplied.

Look for null graphics state and matrices.

R=thestig@chromium.org,dsinclair@chromium.org
BUG=pdfium:532

Review-Url: https://codereview.chromium.org/2120353004

3 files changed, 59 insertions, 5 deletions

diff --git a/core/fpdfapi/fpdf_render/fpdf_render.cpp b/core/fpdfapi/fpdf_render/fpdf_render.cpp
index add2a8ae23..81a02cc6a7 100644
--- a/core/fpdfapi/fpdf_render/fpdf_render.cpp
+++ b/core/fpdfapi/fpdf_render/fpdf_render.cpp
@@ -213,6 +213,9 @@ FX_BOOL CPDF_RenderStatus::Initialize(CPDF_RenderContext* pContext,
 void CPDF_RenderStatus::RenderObjectList(
     const CPDF_PageObjectHolder* pObjectHolder,
     const CFX_Matrix* pObj2Device) {
+#if defined _SKIA_SUPPORT_
+  DebugVerifyDeviceIsPreMultiplied();
+#endif
   CFX_FloatRect clip_rect(m_pDevice->GetClipBox());
   CFX_Matrix device2object;
   device2object.SetReverse(*pObj2Device);
@@ -236,9 +239,16 @@ void CPDF_RenderStatus::RenderObjectList(
     if (m_bStopped)
       return;
   }
+#if defined _SKIA_SUPPORT_
+  DebugVerifyDeviceIsPreMultiplied();
+#endif
 }
+
 void CPDF_RenderStatus::RenderSingleObject(const CPDF_PageObject* pObj,
                                            const CFX_Matrix* pObj2Device) {
+#if defined _SKIA_SUPPORT_
+  DebugVerifyDeviceIsPreMultiplied();
+#endif
   CFX_AutoRestorer<int> restorer(&s_CurrentRecursionDepth);
   if (++s_CurrentRecursionDepth > kRenderMaxRecursionDepth) {
     return;
@@ -254,6 +264,9 @@ void CPDF_RenderStatus::RenderSingleObject(const CPDF_PageObject* pObj,
     return;
   }
   ProcessObjectNoClip(pObj, pObj2Device);
+#if defined _SKIA_SUPPORT_
+  DebugVerifyDeviceIsPreMultiplied();
+#endif
 }
 
 FX_BOOL CPDF_RenderStatus::ContinueSingleObject(const CPDF_PageObject* pObj,
@@ -319,6 +332,9 @@ FX_BOOL CPDF_RenderStatus::GetObjectClippedRect(const CPDF_PageObject* pObj,
 
 void CPDF_RenderStatus::ProcessObjectNoClip(const CPDF_PageObject* pObj,
                                             const CFX_Matrix* pObj2Device) {
+#if defined _SKIA_SUPPORT_
+  DebugVerifyDeviceIsPreMultiplied();
+#endif
   FX_BOOL bRet = FALSE;
   switch (pObj->GetType()) {
     case CPDF_PageObject::TEXT:
@@ -339,6 +355,9 @@ void CPDF_RenderStatus::ProcessObjectNoClip(const CPDF_PageObject* pObj,
   }
   if (!bRet)
     DrawObjWithBackground(pObj, pObj2Device);
+#if defined _SKIA_SUPPORT_
+  DebugVerifyDeviceIsPreMultiplied();
+#endif
 }
 
 FX_BOOL CPDF_RenderStatus::DrawObjWithBlend(const CPDF_PageObject* pObj,
@@ -396,8 +415,12 @@ void CPDF_RenderStatus::DrawObjWithBackground(const CPDF_PageObject* pObj,
   status.RenderSingleObject(pObj, &matrix);
   buffer.OutputToDevice();
 }
+
 FX_BOOL CPDF_RenderStatus::ProcessForm(const CPDF_FormObject* pFormObj,
                                        const CFX_Matrix* pObj2Device) {
+#if defined _SKIA_SUPPORT_
+  DebugVerifyDeviceIsPreMultiplied();
+#endif
   CPDF_Dictionary* pOC = pFormObj->m_pForm->m_pFormDict->GetDictBy("OC");
   if (pOC && m_Options.m_pOCContext &&
       !m_Options.m_pOCContext->CheckOCGVisible(pOC)) {
@@ -418,8 +441,12 @@ FX_BOOL CPDF_RenderStatus::ProcessForm(const CPDF_FormObject* pFormObj,
   status.RenderObjectList(pFormObj->m_pForm, &matrix);
   m_bStopped = status.m_bStopped;
   m_pDevice->RestoreState(false);
+#if defined _SKIA_SUPPORT_
+  DebugVerifyDeviceIsPreMultiplied();
+#endif
   return TRUE;
 }
+
 FX_BOOL IsAvailableMatrix(const CFX_Matrix& matrix) {
   if (matrix.a == 0 || matrix.d == 0) {
     return matrix.b != 0 && matrix.c != 0;
@@ -645,6 +672,9 @@ FX_BOOL CPDF_RenderStatus::SelectClipPath(const CPDF_PathObject* pPathObj,
 }
 FX_BOOL CPDF_RenderStatus::ProcessTransparency(const CPDF_PageObject* pPageObj,
                                                const CFX_Matrix* pObj2Device) {
+#if defined _SKIA_SUPPORT_
+  DebugVerifyDeviceIsPreMultiplied();
+#endif
   const CPDF_GeneralStateData* pGeneralState =
       pPageObj->m_GeneralState.GetObject();
   int blend_type =
@@ -745,12 +775,10 @@ FX_BOOL CPDF_RenderStatus::ProcessTransparency(const CPDF_PageObject* pPageObj,
     oriDevice.reset(new CFX_DIBitmap);
     if (!m_pDevice->CreateCompatibleBitmap(oriDevice.get(), width, height))
       return TRUE;
-
     m_pDevice->GetDIBits(oriDevice.get(), rect.left, rect.top);
   }
   if (!bitmap_device.Create(width, height, FXDIB_Argb, oriDevice.get()))
     return TRUE;
-
   CFX_DIBitmap* bitmap = bitmap_device.GetBitmap();
   bitmap->Clear(0);
   CFX_Matrix new_matrix = *pObj2Device;
@@ -813,6 +841,9 @@ FX_BOOL CPDF_RenderStatus::ProcessTransparency(const CPDF_PageObject* pPageObj,
   }
   CompositeDIBitmap(bitmap, rect.left, rect.top, 0, blitAlpha, blend_type,
                     Transparency);
+#if defined _SKIA_SUPPORT_
+  DebugVerifyDeviceIsPreMultiplied();
+#endif
   return TRUE;
 }
 
@@ -1263,3 +1294,9 @@ void CPDF_ScaledRenderBuffer::OutputToDevice() {
                              m_Rect.top, m_Rect.Width(), m_Rect.Height());
   }
 }
+
+#if defined _SKIA_SUPPORT_
+void CPDF_RenderStatus::DebugVerifyDeviceIsPreMultiplied() const {
+  m_pDevice->DebugVerifyBitmapIsPreMultiplied();
+}
+#endif
diff --git a/core/fpdfapi/fpdf_render/fpdf_render_image.cpp b/core/fpdfapi/fpdf_render/fpdf_render_image.cpp
index 10fd5f3f15..b9826a9338 100644
--- a/core/fpdfapi/fpdf_render/fpdf_render_image.cpp
+++ b/core/fpdfapi/fpdf_render/fpdf_render_image.cpp
@@ -63,8 +63,7 @@ void CPDF_RenderStatus::CompositeDIBitmap(CFX_DIBitmap* pDIBitmap,
 #endif
       }
 #ifdef _SKIA_SUPPORT_
-      static_cast<CFX_SkiaDeviceDriver*>(m_pDevice->GetDeviceDriver())
-          ->PreMultiply(pDIBitmap);
+      CFX_SkiaDeviceDriver::PreMultiply(pDIBitmap);
 #endif
       if (m_pDevice->SetDIBits(pDIBitmap, left, top)) {
         return;
@@ -717,7 +716,7 @@ FX_BOOL CPDF_ImageRenderer::DrawMaskedImage() {
     bitmap_device2.GetBitmap()->ConvertFormat(FXDIB_8bppMask);
     bitmap_device1.GetBitmap()->MultiplyAlpha(bitmap_device2.GetBitmap());
 #ifdef _SKIA_SUPPORT_
-    bitmap_device1.PreMultiply();  // convert unpremultiplied to premultiplied
+    CFX_SkiaDeviceDriver::PreMultiply(bitmap_device1.GetBitmap());
 #endif
     if (m_BitmapAlpha < 255) {
       bitmap_device1.GetBitmap()->MultiplyAlpha(m_BitmapAlpha);
@@ -737,6 +736,19 @@ FX_BOOL CPDF_ImageRenderer::StartDIBSource() {
       m_Flags |= RENDER_FORCE_DOWNSAMPLE;
     }
   }
+#ifdef _SKIA_SUPPORT_
+  CFX_DIBitmap* premultiplied = m_pDIBSource->Clone();
+  CFX_SkiaDeviceDriver::PreMultiply(premultiplied);
+  if (m_pRenderStatus->m_pDevice->StartDIBitsWithBlend(
+          premultiplied, m_BitmapAlpha, m_FillArgb, &m_ImageMatrix, m_Flags,
+          m_DeviceHandle, m_BlendType)) {
+    if (m_DeviceHandle) {
+      m_Status = 3;
+      return TRUE;
+    }
+    return FALSE;
+  }
+#else
   if (m_pRenderStatus->m_pDevice->StartDIBitsWithBlend(
           m_pDIBSource, m_BitmapAlpha, m_FillArgb, &m_ImageMatrix, m_Flags,
           m_DeviceHandle, m_BlendType)) {
@@ -746,6 +758,7 @@ FX_BOOL CPDF_ImageRenderer::StartDIBSource() {
     }
     return FALSE;
   }
+#endif
   CFX_FloatRect image_rect_f = m_ImageMatrix.GetUnitRect();
   FX_RECT image_rect = image_rect_f.GetOutterRect();
   int dest_width = image_rect.Width();
diff --git a/core/fpdfapi/fpdf_render/render_int.h b/core/fpdfapi/fpdf_render/render_int.h
index 67eae91f59..d86a62ab19 100644
--- a/core/fpdfapi/fpdf_render/render_int.h
+++ b/core/fpdfapi/fpdf_render/render_int.h
@@ -150,6 +150,10 @@ class CPDF_RenderStatus {
                                IFX_Pause* pPause);
   CPDF_RenderContext* GetContext() { return m_pContext; }
 
+#if defined _SKIA_SUPPORT_
+  void DebugVerifyDeviceIsPreMultiplied() const;
+#endif
+
   CPDF_RenderOptions m_Options;
   CPDF_Dictionary* m_pFormResource;
   CPDF_Dictionary* m_pPageResource;