From b8a8c43f394277d1f87320a4f01b4d5c38e81113 Mon Sep 17 00:00:00 2001
From: Lei Zhang <thestig@chromium.org>
Date: Thu, 4 May 2017 14:10:50 -0700
Subject: CPDF_Document::GetPageData() normally does not return NULL.

Add a comment to clarify and remove some unneeded checks.

Change-Id: I8b0492548b245abc45e161085047c9f36d6c8e2b
Reviewed-on: https://pdfium-review.googlesource.com/4871
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
---
 core/fpdfapi/page/cpdf_color.cpp     |  3 +--
 core/fpdfapi/page/cpdf_textstate.cpp | 24 ++++++++++++------------
 core/fpdfapi/page/cpdf_textstate.h   |  3 +++
 core/fpdfapi/parser/cpdf_document.h  |  2 ++
 fpdfsdk/fpdfedittext.cpp             | 19 ++++++++++++-------
 5 files changed, 30 insertions(+), 21 deletions(-)

diff --git a/core/fpdfapi/page/cpdf_color.cpp b/core/fpdfapi/page/cpdf_color.cpp
index 6e772aadb1..ca0e621530 100644
--- a/core/fpdfapi/page/cpdf_color.cpp
+++ b/core/fpdfapi/page/cpdf_color.cpp
@@ -91,8 +91,7 @@ void CPDF_Color::SetValue(CPDF_Pattern* pPattern, float* comps, int ncomps) {
   PatternValue* pvalue = (PatternValue*)m_pBuffer;
   if (pvalue->m_pPattern) {
     pDocPageData = pvalue->m_pPattern->document()->GetPageData();
-    if (pDocPageData)
-      pDocPageData->ReleasePattern(pvalue->m_pPattern->pattern_obj());
+    pDocPageData->ReleasePattern(pvalue->m_pPattern->pattern_obj());
   }
   pvalue->m_nComps = ncomps;
   pvalue->m_pPattern = pPattern;
diff --git a/core/fpdfapi/page/cpdf_textstate.cpp b/core/fpdfapi/page/cpdf_textstate.cpp
index 6dbad55ba6..bd236a2f28 100644
--- a/core/fpdfapi/page/cpdf_textstate.cpp
+++ b/core/fpdfapi/page/cpdf_textstate.cpp
@@ -115,25 +115,16 @@ CPDF_TextState::TextData::TextData(const TextData& that)
   for (int i = 0; i < 4; ++i)
     m_CTM[i] = that.m_CTM[i];
 
-  if (m_pDocument && m_pFont) {
+  if (m_pDocument && m_pFont)
     m_pFont = m_pDocument->GetPageData()->GetFont(m_pFont->GetFontDict());
-  }
 }
 
 CPDF_TextState::TextData::~TextData() {
-  if (m_pDocument && m_pFont) {
-    CPDF_DocPageData* pPageData = m_pDocument->GetPageData();
-    if (pPageData && !pPageData->IsForceClear())
-      pPageData->ReleaseFont(m_pFont->GetFontDict());
-  }
+  ReleaseFont();
 }
 
 void CPDF_TextState::TextData::SetFont(CPDF_Font* pFont) {
-  CPDF_Document* pDoc = m_pDocument;
-  CPDF_DocPageData* pPageData = pDoc ? pDoc->GetPageData() : nullptr;
-  if (pPageData && m_pFont && !pPageData->IsForceClear())
-    pPageData->ReleaseFont(m_pFont->GetFontDict());
-
+  ReleaseFont();
   m_pDocument = pFont ? pFont->GetDocument() : nullptr;
   m_pFont = pFont;
 }
@@ -154,6 +145,15 @@ float CPDF_TextState::TextData::GetShearAngle() const {
   return GetBaselineAngle() + atan2(m_Matrix[1], m_Matrix[3]);
 }
 
+void CPDF_TextState::TextData::ReleaseFont() {
+  if (!m_pDocument || !m_pFont)
+    return;
+
+  CPDF_DocPageData* pPageData = m_pDocument->GetPageData();
+  if (pPageData && !pPageData->IsForceClear())
+    pPageData->ReleaseFont(m_pFont->GetFontDict());
+}
+
 bool SetTextRenderingModeFromInt(int iMode, TextRenderingMode* mode) {
   if (iMode < 0 || iMode > 7)
     return false;
diff --git a/core/fpdfapi/page/cpdf_textstate.h b/core/fpdfapi/page/cpdf_textstate.h
index 07bee5ed04..84d2c13a6c 100644
--- a/core/fpdfapi/page/cpdf_textstate.h
+++ b/core/fpdfapi/page/cpdf_textstate.h
@@ -79,6 +79,9 @@ class CPDF_TextState {
     TextRenderingMode m_TextMode;
     float m_Matrix[4];
     float m_CTM[4];
+
+   private:
+    void ReleaseFont();
   };
 
   CFX_SharedCopyOnWrite<TextData> m_Ref;
diff --git a/core/fpdfapi/parser/cpdf_document.h b/core/fpdfapi/parser/cpdf_document.h
index 2f54ba7c28..f7fb6308c1 100644
--- a/core/fpdfapi/parser/cpdf_document.h
+++ b/core/fpdfapi/parser/cpdf_document.h
@@ -58,6 +58,8 @@ class CPDF_Document : public CPDF_IndirectObjectHolder {
   CPDF_Dictionary* GetPage(int iPage);
   int GetPageIndex(uint32_t objnum);
   uint32_t GetUserPermissions() const;
+
+  // Returns a valid pointer, unless it is called during destruction.
   CPDF_DocPageData* GetPageData() const { return m_pDocPage.get(); }
 
   void SetPageObjNum(int iPage, uint32_t objNum);
diff --git a/fpdfsdk/fpdfedittext.cpp b/fpdfsdk/fpdfedittext.cpp
index 4ff2269c9e..9b01775235 100644
--- a/fpdfsdk/fpdfedittext.cpp
+++ b/fpdfsdk/fpdfedittext.cpp
@@ -431,23 +431,28 @@ DLLEXPORT void STDCALL FPDFFont_Close(FPDF_FONT font) {
   if (!font)
     return;
 
-  CPDF_Font* cpdf_font = reinterpret_cast<CPDF_Font*>(font);
-  CPDF_Document* pDoc = cpdf_font->GetDocument();
-  CPDF_DocPageData* pPageData = pDoc ? pDoc->GetPageData() : nullptr;
-  if (pPageData && !pPageData->IsForceClear())
-    pPageData->ReleaseFont(cpdf_font->GetFontDict());
+  CPDF_Font* pFont = reinterpret_cast<CPDF_Font*>(font);
+  CPDF_Document* pDoc = pFont->GetDocument();
+  if (!pDoc)
+    return;
+
+  CPDF_DocPageData* pPageData = pDoc->GetPageData();
+  if (!pPageData->IsForceClear())
+    pPageData->ReleaseFont(pFont->GetFontDict());
 }
 
 DLLEXPORT FPDF_PAGEOBJECT STDCALL
 FPDFPageObj_CreateTextObj(FPDF_DOCUMENT document,
                           FPDF_FONT font,
                           float font_size) {
+  if (!font)
+    return nullptr;
+
   CPDF_Document* pDoc = CPDFDocumentFromFPDFDocument(document);
-  if (!pDoc || !font)
+  if (!pDoc)
     return nullptr;
 
   CPDF_Font* pFont = reinterpret_cast<CPDF_Font*>(font);
-
   auto pTextObj = pdfium::MakeUnique<CPDF_TextObject>();
   pTextObj->m_TextState.SetFont(pDoc->LoadFont(pFont->GetFontDict()));
   pTextObj->m_TextState.SetFontSize(font_size);
-- 
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