Remove CFX_ArrayTemplate from CPDF_LinkExtract

Use unqiue_ptrs while we're at it, also better ctor.

Review URL: https://codereview.chromium.org/1896303002

6 files changed, 114 insertions, 207 deletions

diff --git a/core/fpdftext/fpdf_text_int.cpp b/core/fpdftext/fpdf_text_int.cpp
index 741331fb77..4db4d5c09f 100644
--- a/core/fpdftext/fpdf_text_int.cpp
+++ b/core/fpdftext/fpdf_text_int.cpp
@@ -262,7 +262,7 @@ int CPDF_TextPage::TextIndexFromCharIndex(int CharIndex) const {
 
 void CPDF_TextPage::GetRectArray(int start,
                                  int nCount,
-                                 CFX_RectArray& rectArray) const {
+                                 CFX_RectArray* rectArray) const {
   if (start < 0 || nCount == 0) {
     return;
   }
@@ -290,7 +290,7 @@ void CPDF_TextPage::GetRectArray(int start,
       pCurObj = info_curchar.m_pTextObj;
     }
     if (pCurObj != info_curchar.m_pTextObj) {
-      rectArray.Add(rect);
+      rectArray->Add(rect);
       pCurObj = info_curchar.m_pTextObj;
       flagNewRect = TRUE;
     }
@@ -343,7 +343,7 @@ void CPDF_TextPage::GetRectArray(int start,
       }
     }
   }
-  rectArray.Add(rect);
+  rectArray->Add(rect);
 }
 
 int CPDF_TextPage::GetIndexAtPos(CFX_FloatPoint point,
@@ -592,7 +592,7 @@ int CPDF_TextPage::CountRects(int start, int nCount) {
     nCount = pdfium::CollectionSize<int>(m_CharList) - start;
   }
   m_SelRects.RemoveAll();
-  GetRectArray(start, nCount, m_SelRects);
+  GetRectArray(start, nCount, &m_SelRects);
   return m_SelRects.GetSize();
 }
 
@@ -649,35 +649,6 @@ FX_BOOL CPDF_TextPage::GetBaselineRotate(int start, int end, int& Rotate) {
   return TRUE;
 }
 
-FX_BOOL CPDF_TextPage::GetBaselineRotate(const CFX_FloatRect& rect,
-                                         int& Rotate) {
-  int start, end, count,
-      n = CountBoundedSegments(rect.left, rect.top, rect.right, rect.bottom,
-                               TRUE);
-  if (n < 1) {
-    return FALSE;
-  }
-  if (n > 1) {
-    GetBoundedSegment(n - 1, start, count);
-    end = start + count - 1;
-    GetBoundedSegment(0, start, count);
-  } else {
-    GetBoundedSegment(0, start, count);
-    end = start + count - 1;
-  }
-  return GetBaselineRotate(start, end, Rotate);
-}
-FX_BOOL CPDF_TextPage::GetBaselineRotate(int rectIndex, int& Rotate) {
-  if (!m_bIsParsed)
-    return FALSE;
-
-  if (rectIndex < 0 || rectIndex >= m_SelRects.GetSize())
-    return FALSE;
-
-  CFX_FloatRect rect = m_SelRects.GetAt(rectIndex);
-  return GetBaselineRotate(rect, Rotate);
-}
-
 int CPDF_TextPage::CountBoundedSegments(FX_FLOAT left,
                                         FX_FLOAT top,
                                         FX_FLOAT right,
@@ -756,14 +727,6 @@ int CPDF_TextPage::CountBoundedSegments(FX_FLOAT left,
   return m_Segments.GetSize();
 }
 
-void CPDF_TextPage::GetBoundedSegment(int index, int& start, int& count) const {
-  if (index < 0 || index >= m_Segments.GetSize()) {
-    return;
-  }
-  start = m_Segments.GetAt(index).m_Start;
-  count = m_Segments.GetAt(index).m_nCount;
-}
-
 int CPDF_TextPage::GetWordBreak(int index, int direction) const {
   if (!m_bIsParsed)
     return -1;
@@ -2126,7 +2089,7 @@ FX_BOOL CPDF_TextPageFind::FindNext() {
   m_IsFind = TRUE;
   int resStart = GetCharIndex(m_resStart);
   int resEnd = GetCharIndex(m_resEnd);
-  m_pTextPage->GetRectArray(resStart, resEnd - resStart + 1, m_resArray);
+  m_pTextPage->GetRectArray(resStart, resEnd - resStart + 1, &m_resArray);
   if (m_flags & FPDFTEXT_CONSECUTIVE) {
     m_findNextStart = m_resStart + 1;
     m_findPreStart = m_resEnd - 1;
@@ -2172,7 +2135,7 @@ FX_BOOL CPDF_TextPageFind::FindPrev() {
   m_resStart = m_pTextPage->TextIndexFromCharIndex(order);
   m_resEnd = m_pTextPage->TextIndexFromCharIndex(order + MatchedCount - 1);
   m_IsFind = TRUE;
-  m_pTextPage->GetRectArray(order, MatchedCount, m_resArray);
+  m_pTextPage->GetRectArray(order, MatchedCount, &m_resArray);
   if (m_flags & FPDFTEXT_CONSECUTIVE) {
     m_findNextStart = m_resStart + 1;
     m_findPreStart = m_resEnd - 1;
@@ -2330,43 +2293,22 @@ int CPDF_TextPageFind::GetMatchedCount() const {
   return resEnd - resStart + 1;
 }
 
-CPDF_LinkExtract::CPDF_LinkExtract()
-    : m_pTextPage(nullptr), m_bIsParsed(false) {}
+CPDF_LinkExtract::CPDF_LinkExtract(const CPDF_TextPage* pTextPage)
+    : m_pTextPage(pTextPage) {}
 
 CPDF_LinkExtract::~CPDF_LinkExtract() {
-  DeleteLinkList();
 }
 
-FX_BOOL CPDF_LinkExtract::ExtractLinks(const CPDF_TextPage* pTextPage) {
-  if (!pTextPage || !pTextPage->IsParsed())
-    return FALSE;
+void CPDF_LinkExtract::ExtractLinks() {
+  m_LinkArray.clear();
+  if (!m_pTextPage->IsParsed())
+    return;
 
-  m_pTextPage = (const CPDF_TextPage*)pTextPage;
   m_strPageText = m_pTextPage->GetPageText(0, -1);
-  DeleteLinkList();
-  if (m_strPageText.IsEmpty()) {
-    return FALSE;
-  }
-  ParseLink();
-  m_bIsParsed = true;
-  return TRUE;
-}
-
-void CPDF_LinkExtract::DeleteLinkList() {
-  while (m_LinkList.GetSize()) {
-    CPDF_LinkExt* linkinfo = NULL;
-    linkinfo = m_LinkList.GetAt(0);
-    m_LinkList.RemoveAt(0);
-    delete linkinfo;
-  }
-  m_LinkList.RemoveAll();
-}
+  if (m_strPageText.IsEmpty())
+    return;
 
-int CPDF_LinkExtract::CountLinks() const {
-  if (!m_bIsParsed) {
-    return -1;
-  }
-  return m_LinkList.GetSize();
+  ParseLink();
 }
 
 void CPDF_LinkExtract::ParseLink() {
@@ -2395,7 +2337,7 @@ void CPDF_LinkExtract::ParseLink() {
         }
         if (nCount > 5 &&
             (CheckWebLink(strBeCheck) || CheckMailLink(strBeCheck))) {
-          AppendToLinkList(start, nCount, strBeCheck);
+          m_LinkArray.push_back({start, nCount, strBeCheck});
         }
       }
       start = ++pos;
@@ -2405,47 +2347,46 @@ void CPDF_LinkExtract::ParseLink() {
   }
 }
 
-FX_BOOL CPDF_LinkExtract::CheckWebLink(CFX_WideString& strBeCheck) {
+bool CPDF_LinkExtract::CheckWebLink(CFX_WideString& strBeCheck) {
   CFX_WideString str = strBeCheck;
   str.MakeLower();
   if (str.Find(L"http://www.") != -1) {
     strBeCheck = strBeCheck.Right(str.GetLength() - str.Find(L"http://www."));
-    return TRUE;
+    return true;
   }
   if (str.Find(L"http://") != -1) {
     strBeCheck = strBeCheck.Right(str.GetLength() - str.Find(L"http://"));
-    return TRUE;
+    return true;
   }
   if (str.Find(L"https://www.") != -1) {
     strBeCheck = strBeCheck.Right(str.GetLength() - str.Find(L"https://www."));
-    return TRUE;
+    return true;
   }
   if (str.Find(L"https://") != -1) {
     strBeCheck = strBeCheck.Right(str.GetLength() - str.Find(L"https://"));
-    return TRUE;
+    return true;
   }
   if (str.Find(L"www.") != -1) {
     strBeCheck = strBeCheck.Right(str.GetLength() - str.Find(L"www."));
     strBeCheck = L"http://" + strBeCheck;
-    return TRUE;
+    return true;
   }
-  return FALSE;
+  return false;
 }
 
 bool CPDF_LinkExtract::CheckMailLink(CFX_WideString& str) {
   int aPos = str.Find(L'@');
   // Invalid when no '@'.
-  if (aPos < 1) {
-    return FALSE;
-  }
+  if (aPos < 1)
+    return false;
 
   // Check the local part.
   int pPos = aPos;  // Used to track the position of '@' or '.'.
   for (int i = aPos - 1; i >= 0; i--) {
     FX_WCHAR ch = str.GetAt(i);
-    if (ch == L'_' || ch == L'-' || FXSYS_iswalnum(ch)) {
+    if (ch == L'_' || ch == L'-' || FXSYS_iswalnum(ch))
       continue;
-    }
+
     if (ch != L'.' || i == pPos - 1 || i == 0) {
       if (i == aPos - 1) {
         // There is '.' or invalid char before '@'.
@@ -2463,25 +2404,25 @@ bool CPDF_LinkExtract::CheckMailLink(CFX_WideString& str) {
 
   // Check the domain name part.
   aPos = str.Find(L'@');
-  if (aPos < 1) {
-    return FALSE;
-  }
+  if (aPos < 1)
+    return false;
+
   str.TrimRight(L'.');
   // At least one '.' in domain name, but not at the beginning.
   // TODO(weili): RFC5322 allows domain names to be a local name without '.'.
   // Check whether we should remove this check.
   int ePos = str.Find(L'.', aPos + 1);
-  if (ePos == -1 || ePos == aPos + 1) {
-    return FALSE;
-  }
+  if (ePos == -1 || ePos == aPos + 1)
+    return false;
+
   // Validate all other chars in domain name.
   int nLen = str.GetLength();
   pPos = 0;  // Used to track the position of '.'.
   for (int i = aPos + 1; i < nLen; i++) {
     FX_WCHAR wch = str.GetAt(i);
-    if (wch == L'-' || FXSYS_iswalnum(wch)) {
+    if (wch == L'-' || FXSYS_iswalnum(wch))
       continue;
-    }
+
     if (wch != L'.' || i == pPos + 1) {
       // Domain name should end before invalid char.
       int host_end = i == pPos + 1 ? i - 2 : i - 1;
@@ -2490,61 +2431,24 @@ bool CPDF_LinkExtract::CheckMailLink(CFX_WideString& str) {
         str = str.Left(host_end + 1);
         break;
       }
-      return FALSE;
+      return false;
     }
     pPos = i;
   }
 
-  if (str.Find(L"mailto:") == -1) {
+  if (str.Find(L"mailto:") == -1)
     str = L"mailto:" + str;
-  }
-  return TRUE;
-}
 
-void CPDF_LinkExtract::AppendToLinkList(int start,
-                                        int count,
-                                        const CFX_WideString& strUrl) {
-  CPDF_LinkExt* linkInfo = new CPDF_LinkExt;
-  linkInfo->m_strUrl = strUrl;
-  linkInfo->m_Start = start;
-  linkInfo->m_Count = count;
-  m_LinkList.Add(linkInfo);
+  return true;
 }
 
-CFX_WideString CPDF_LinkExtract::GetURL(int index) const {
-  if (!m_bIsParsed || index < 0 || index >= m_LinkList.GetSize()) {
-    return L"";
-  }
-  CPDF_LinkExt* link = NULL;
-  link = m_LinkList.GetAt(index);
-  if (!link) {
-    return L"";
-  }
-  return link->m_strUrl;
-}
-void CPDF_LinkExtract::GetBoundedSegment(int index,
-                                         int& start,
-                                         int& count) const {
-  if (!m_bIsParsed || index < 0 || index >= m_LinkList.GetSize()) {
-    return;
-  }
-  CPDF_LinkExt* link = NULL;
-  link = m_LinkList.GetAt(index);
-  if (!link) {
-    return;
-  }
-  start = link->m_Start;
-  count = link->m_Count;
+CFX_WideString CPDF_LinkExtract::GetURL(size_t index) const {
+  return index < m_LinkArray.size() ? m_LinkArray[index].m_strUrl : L"";
 }
 
-void CPDF_LinkExtract::GetRects(int index, CFX_RectArray& rects) const {
-  if (!m_bIsParsed || index < 0 || index >= m_LinkList.GetSize()) {
-    return;
-  }
-  CPDF_LinkExt* link = NULL;
-  link = m_LinkList.GetAt(index);
-  if (!link) {
-    return;
+void CPDF_LinkExtract::GetRects(size_t index, CFX_RectArray* pRects) const {
+  if (index < m_LinkArray.size()) {
+    m_pTextPage->GetRectArray(m_LinkArray[index].m_Start,
+                              m_LinkArray[index].m_Count, pRects);
   }
-  m_pTextPage->GetRectArray(link->m_Start, link->m_Count, rects);
 }
diff --git a/core/fpdftext/fpdf_text_int_unittest.cpp b/core/fpdftext/fpdf_text_int_unittest.cpp
index e1dd0f7504..0ee11d2d57 100644
--- a/core/fpdftext/fpdf_text_int_unittest.cpp
+++ b/core/fpdftext/fpdf_text_int_unittest.cpp
@@ -8,6 +8,9 @@
 
 // Class to help test functions in CPDF_LinkExtract class.
 class CPDF_TestLinkExtract : public CPDF_LinkExtract {
+ public:
+  CPDF_TestLinkExtract() : CPDF_LinkExtract(nullptr) {}
+
  private:
   // Add test cases as friends to access protected member functions.
   // Access CheckMailLink.
diff --git a/core/fpdftext/include/cpdf_linkextract.h b/core/fpdftext/include/cpdf_linkextract.h
index 263768ee5d..4f9537c799 100644
--- a/core/fpdftext/include/cpdf_linkextract.h
+++ b/core/fpdftext/include/cpdf_linkextract.h
@@ -7,6 +7,8 @@
 #ifndef CORE_FPDFTEXT_INCLUDE_CPDF_LINKEXTRACT_H_
 #define CORE_FPDFTEXT_INCLUDE_CPDF_LINKEXTRACT_H_
 
+#include <vector>
+
 #include "core/fxcrt/include/fx_basic.h"
 #include "core/fxcrt/include/fx_coordinates.h"
 #include "core/fxcrt/include/fx_string.h"
@@ -14,41 +16,31 @@
 
 class CPDF_TextPage;
 
-class CPDF_LinkExt {
- public:
-  CPDF_LinkExt() {}
-  ~CPDF_LinkExt() {}
-
-  int m_Start;
-  int m_Count;
-  CFX_WideString m_strUrl;
-};
-
 class CPDF_LinkExtract {
  public:
-  CPDF_LinkExtract();
+  explicit CPDF_LinkExtract(const CPDF_TextPage* pTextPage);
   ~CPDF_LinkExtract();
 
-  FX_BOOL ExtractLinks(const CPDF_TextPage* pTextPage);
-  int CountLinks() const;
-  CFX_WideString GetURL(int index) const;
-  void GetBoundedSegment(int index, int& start, int& count) const;
-  void GetRects(int index, CFX_RectArray& rects) const;
-
-  FX_BOOL IsExtract() const { return m_bIsParsed; }
+  void ExtractLinks();
+  size_t CountLinks() const { return m_LinkArray.size(); }
+  CFX_WideString GetURL(size_t index) const;
+  void GetRects(size_t index, CFX_RectArray* pRects) const;
 
  protected:
   void ParseLink();
-  void DeleteLinkList();
-  FX_BOOL CheckWebLink(CFX_WideString& strBeCheck);
+  bool CheckWebLink(CFX_WideString& str);
   bool CheckMailLink(CFX_WideString& str);
-  void AppendToLinkList(int start, int count, const CFX_WideString& strUrl);
 
  private:
-  CFX_ArrayTemplate<CPDF_LinkExt*> m_LinkList;
-  const CPDF_TextPage* m_pTextPage;
+  struct Link {
+    int m_Start;
+    int m_Count;
+    CFX_WideString m_strUrl;
+  };
+
+  const CPDF_TextPage* const m_pTextPage;
   CFX_WideString m_strPageText;
-  bool m_bIsParsed;
+  std::vector<Link> m_LinkArray;
 };
 
 #endif  // CORE_FPDFTEXT_INCLUDE_CPDF_LINKEXTRACT_H_
diff --git a/core/fpdftext/include/cpdf_textpage.h b/core/fpdftext/include/cpdf_textpage.h
index 19e8791b5a..8d608b0bf0 100644
--- a/core/fpdftext/include/cpdf_textpage.h
+++ b/core/fpdftext/include/cpdf_textpage.h
@@ -67,7 +67,7 @@ class CPDF_TextPage {
   int TextIndexFromCharIndex(int CharIndex) const;
   int CountChars() const;
   void GetCharInfo(int index, FPDF_CHAR_INFO* info) const;
-  void GetRectArray(int start, int nCount, CFX_RectArray& rectArray) const;
+  void GetRectArray(int start, int nCount, CFX_RectArray* rectArray) const;
   int GetIndexAtPos(CFX_FloatPoint point,
                     FX_FLOAT xTolerance,
                     FX_FLOAT yTolerance) const;
@@ -85,14 +85,12 @@ class CPDF_TextPage {
                FX_FLOAT& top,
                FX_FLOAT& right,
                FX_FLOAT& bottom) const;
-  FX_BOOL GetBaselineRotate(int rectIndex, int& Rotate);
-  FX_BOOL GetBaselineRotate(const CFX_FloatRect& rect, int& Rotate);
   int CountBoundedSegments(FX_FLOAT left,
                            FX_FLOAT top,
                            FX_FLOAT right,
                            FX_FLOAT bottom,
                            FX_BOOL bContains = FALSE);
-  void GetBoundedSegment(int index, int& start, int& count) const;
+
   int GetWordBreak(int index, int direction) const;
 
   static FX_BOOL IsRectIntersect(const CFX_FloatRect& rect1,
diff --git a/fpdfsdk/fpdftext.cpp b/fpdfsdk/fpdftext.cpp
index 007e18274e..2a84131422 100644
--- a/fpdfsdk/fpdftext.cpp
+++ b/fpdfsdk/fpdftext.cpp
@@ -12,6 +12,7 @@
 #include "core/fpdftext/include/cpdf_textpage.h"
 #include "core/fpdftext/include/cpdf_textpagefind.h"
 #include "fpdfsdk/include/fsdk_define.h"
+#include "third_party/base/numerics/safe_conversions.h"
 
 #ifdef PDF_ENABLE_XFA
 #include "fpdfsdk/fpdfxfa/include/fpdfxfa_doc.h"
@@ -273,8 +274,9 @@ DLLEXPORT FPDF_PAGELINK STDCALL FPDFLink_LoadWebLinks(FPDF_TEXTPAGE text_page) {
   if (!text_page)
     return nullptr;
 
-  CPDF_LinkExtract* pageLink = new CPDF_LinkExtract;
-  pageLink->ExtractLinks(CPDFTextPageFromFPDFTextPage(text_page));
+  CPDF_LinkExtract* pageLink =
+      new CPDF_LinkExtract(CPDFTextPageFromFPDFTextPage(text_page));
+  pageLink->ExtractLinks();
   return pageLink;
 }
 
@@ -283,42 +285,40 @@ DLLEXPORT int STDCALL FPDFLink_CountWebLinks(FPDF_PAGELINK link_page) {
     return 0;
 
   CPDF_LinkExtract* pageLink = CPDFLinkExtractFromFPDFPageLink(link_page);
-  return pageLink->CountLinks();
+  return pdfium::base::checked_cast<int>(pageLink->CountLinks());
 }
 
 DLLEXPORT int STDCALL FPDFLink_GetURL(FPDF_PAGELINK link_page,
                                       int link_index,
                                       unsigned short* buffer,
                                       int buflen) {
-  if (!link_page)
-    return 0;
-
-  CPDF_LinkExtract* pageLink = CPDFLinkExtractFromFPDFPageLink(link_page);
-  CFX_WideString url = pageLink->GetURL(link_index);
-
-  CFX_ByteString cbUTF16URL = url.UTF16LE_Encode();
-  int len = cbUTF16URL.GetLength() / sizeof(unsigned short);
+  CFX_WideString wsUrl(L"");
+  if (link_page && link_index >= 0) {
+    CPDF_LinkExtract* pageLink = CPDFLinkExtractFromFPDFPageLink(link_page);
+    wsUrl = pageLink->GetURL(link_index);
+  }
+  CFX_ByteString cbUTF16URL = wsUrl.UTF16LE_Encode();
+  int required = cbUTF16URL.GetLength() / sizeof(unsigned short);
   if (!buffer || buflen <= 0)
-    return len;
+    return required;
 
-  int size = len < buflen ? len : buflen;
+  int size = std::min(required, buflen);
   if (size > 0) {
     int buf_size = size * sizeof(unsigned short);
     FXSYS_memcpy(buffer, cbUTF16URL.GetBuffer(buf_size), buf_size);
-    cbUTF16URL.ReleaseBuffer(buf_size);
   }
   return size;
 }
 
 DLLEXPORT int STDCALL FPDFLink_CountRects(FPDF_PAGELINK link_page,
                                           int link_index) {
-  if (!link_page)
+  if (!link_page || link_index < 0)
     return 0;
 
+  CFX_RectArray rects;
   CPDF_LinkExtract* pageLink = CPDFLinkExtractFromFPDFPageLink(link_page);
-  CFX_RectArray rectArray;
-  pageLink->GetRects(link_index, rectArray);
-  return rectArray.GetSize();
+  pageLink->GetRects(link_index, &rects);
+  return rects.GetSize();
 }
 
 DLLEXPORT void STDCALL FPDFLink_GetRect(FPDF_PAGELINK link_page,
@@ -328,20 +328,22 @@ DLLEXPORT void STDCALL FPDFLink_GetRect(FPDF_PAGELINK link_page,
                                         double* top,
                                         double* right,
                                         double* bottom) {
-  if (!link_page)
+  if (!link_page || link_index < 0 || rect_index < 0)
     return;
 
-  CPDF_LinkExtract* pageLink = CPDFLinkExtractFromFPDFPageLink(link_page);
   CFX_RectArray rectArray;
-  pageLink->GetRects(link_index, rectArray);
-  if (rect_index >= 0 && rect_index < rectArray.GetSize()) {
-    CFX_FloatRect rect = rectArray.GetAt(rect_index);
-    *left = rect.left;
-    *right = rect.right;
-    *top = rect.top;
-    *bottom = rect.bottom;
-  }
+  CPDF_LinkExtract* pageLink = CPDFLinkExtractFromFPDFPageLink(link_page);
+  pageLink->GetRects(link_index, &rectArray);
+  if (rect_index >= rectArray.GetSize())
+    return;
+
+  CFX_FloatRect rect = rectArray.GetAt(rect_index);
+  *left = rect.left;
+  *right = rect.right;
+  *top = rect.top;
+  *bottom = rect.bottom;
 }
+
 DLLEXPORT void STDCALL FPDFLink_CloseWebLinks(FPDF_PAGELINK link_page) {
   delete CPDFLinkExtractFromFPDFPageLink(link_page);
 }
diff --git a/public/fpdf_text.h b/public/fpdf_text.h
index 32cc131859..2bf574b12f 100644
--- a/public/fpdf_text.h
+++ b/public/fpdf_text.h
@@ -351,13 +351,19 @@ DLLEXPORT int STDCALL FPDFLink_CountWebLinks(FPDF_PAGELINK link_page);
 // Parameters:
 //          link_page   -   Handle returned by FPDFLink_LoadWebLinks.
 //          link_index  -   Zero-based index for the link.
-//          buffer      -   A unicode buffer.
+//          buffer      -   A unicode buffer for the result.
 //          buflen      -   Number of characters (not bytes) for the buffer,
-//          including an additional terminator.
+//                          including an additional terminator.
 // Return Value:
-//          If buffer is NULL or buflen is zero, return number of characters
-//          (not bytes and an additional terminator is also counted) needed,
-//          otherwise, return number of characters copied into the buffer.
+//          If |buffer| is NULL or |buflen| is zero, return the number of
+//          characters (not bytes) needed to buffer the result (an additional
+//          terminator is included in this count).
+//          Otherwise, copy the result into |buffer|, truncating at |buflen| if
+//          the result is too large to fit, and return the number of characters
+//          actually copied into the buffer (the additional terminator is also
+//          included in this count).
+//          If |link_index| does not correspond to a valid link, then the result
+//          is an empty string.
 //
 DLLEXPORT int STDCALL FPDFLink_GetURL(FPDF_PAGELINK link_page,
                                       int link_index,
@@ -370,7 +376,8 @@ DLLEXPORT int STDCALL FPDFLink_GetURL(FPDF_PAGELINK link_page,
 //          link_page   -   Handle returned by FPDFLink_LoadWebLinks.
 //          link_index  -   Zero-based index for the link.
 // Return Value:
-//          Number of rectangular areas for the link.
+//          Number of rectangular areas for the link.  If |link_index| does
+//          not correspond to a valid link, then 0 is returned.
 //
 DLLEXPORT int STDCALL FPDFLink_CountRects(FPDF_PAGELINK link_page,
                                           int link_index);
@@ -382,15 +389,16 @@ DLLEXPORT int STDCALL FPDFLink_CountRects(FPDF_PAGELINK link_page,
 //          link_index  -   Zero-based index for the link.
 //          rect_index  -   Zero-based index for a rectangle.
 //          left        -   Pointer to a double value receiving the rectangle
-//          left boundary.
+//                          left boundary.
 //          top         -   Pointer to a double value receiving the rectangle
-//          top boundary.
+//                          top boundary.
 //          right       -   Pointer to a double value receiving the rectangle
-//          right boundary.
+//                          right boundary.
 //          bottom      -   Pointer to a double value receiving the rectangle
-//          bottom boundary.
+//                          bottom boundary.
 // Return Value:
-//          None.
+//          None.  If |link_index| does not correspond to a valid link, then
+//          |left|, |top|, |right|, and |bottom| remain unmodified.
 //
 DLLEXPORT void STDCALL FPDFLink_GetRect(FPDF_PAGELINK link_page,
                                         int link_index,