From c831580e1b4547d5fcbe74864e657c1c4ebffc12 Mon Sep 17 00:00:00 2001
From: Henrique Nakashima <hnakashima@chromium.org>
Date: Thu, 19 Apr 2018 21:59:33 +0000
Subject: Fix duplicated text in each line in XFA widgets.

When calculating the characters to display, the run offset was not
added to the offset inside the run, so characters from the first run
were always used instead of from the run that the line should display.

Bug: chromium:832909
Change-Id: I4d1d284894ce6ac9c7a49976aa6a6d0cf21f1382
Reviewed-on: https://pdfium-review.googlesource.com/30993
Commit-Queue: Henrique Nakashima <hnakashima@chromium.org>
Reviewed-by: dsinclair <dsinclair@chromium.org>
---
 xfa/fde/cfde_texteditengine.cpp  |  2 ++
 xfa/fgas/layout/cfx_txtbreak.cpp | 19 ++++++++++++-------
 xfa/fgas/layout/cfx_txtbreak.h   |  1 +
 3 files changed, 15 insertions(+), 7 deletions(-)

diff --git a/xfa/fde/cfde_texteditengine.cpp b/xfa/fde/cfde_texteditengine.cpp
index ac66fd7f99..a423ba6eb4 100644
--- a/xfa/fde/cfde_texteditengine.cpp
+++ b/xfa/fde/cfde_texteditengine.cpp
@@ -953,6 +953,7 @@ std::vector<CFX_RectF> CFDE_TextEditEngine::GetCharRects(
 
   FX_TXTRUN tr;
   tr.pEdtEngine = this;
+  tr.iStart = piece.nStart;
   tr.iLength = piece.nCount;
   tr.pFont = font_;
   tr.fFontSize = font_size_;
@@ -969,6 +970,7 @@ std::vector<FXTEXT_CHARPOS> CFDE_TextEditEngine::GetDisplayPos(
 
   FX_TXTRUN tr;
   tr.pEdtEngine = this;
+  tr.iStart = piece.nStart;
   tr.iLength = piece.nCount;
   tr.pFont = font_;
   tr.fFontSize = font_size_;
diff --git a/xfa/fgas/layout/cfx_txtbreak.cpp b/xfa/fgas/layout/cfx_txtbreak.cpp
index c3075b00dc..ccbc6a817a 100644
--- a/xfa/fgas/layout/cfx_txtbreak.cpp
+++ b/xfa/fgas/layout/cfx_txtbreak.cpp
@@ -686,11 +686,12 @@ int32_t CFX_TxtBreak::GetDisplayPos(const FX_TXTRUN* pTxtRun,
   bool bShadda = false;
   bool bLam = false;
   for (int32_t i = 0; i <= iLength; i++) {
+    int32_t iAbsolute = i + pTxtRun->iStart;
     int32_t iWidth;
     wchar_t wch;
     if (pEngine) {
-      wch = pEngine->GetChar(i);
-      iWidth = pEngine->GetWidthOfChar(i);
+      wch = pEngine->GetChar(iAbsolute);
+      iWidth = pEngine->GetWidthOfChar(iAbsolute);
     } else {
       wch = *pStr++;
       iWidth = *pWidths++;
@@ -709,7 +710,8 @@ int32_t CFX_TxtBreak::GetDisplayPos(const FX_TXTRUN* pTxtRun,
         if (pEngine) {
           iNext = i + 1;
           while (iNext <= iLength) {
-            wNext = pEngine->GetChar(iNext);
+            int32_t iNextAbsolute = iNext + pTxtRun->iStart;
+            wNext = pEngine->GetChar(iNextAbsolute);
             dwProps = FX_GetUnicodeProperties(wNext);
             if ((dwProps & FX_CHARTYPEBITSMASK) != FX_CHARTYPE_Combination)
               break;
@@ -747,8 +749,10 @@ int32_t CFX_TxtBreak::GetDisplayPos(const FX_TXTRUN* pTxtRun,
           wNext = 0xFEFF;
           if (pEngine) {
             iNext = i + 1;
-            if (iNext <= iLength)
-              wNext = pEngine->GetChar(iNext);
+            if (iNext <= iLength) {
+              int32_t iNextAbsolute = iNext + pTxtRun->iStart;
+              wNext = pEngine->GetChar(iNextAbsolute);
+            }
           } else {
             if (i < iLength)
               wNext = *pStr;
@@ -930,9 +934,10 @@ std::vector<CFX_RectF> CFX_TxtBreak::GetCharRects(const FX_TXTRUN* pTxtRun,
 
   std::vector<CFX_RectF> rtArray(iLength);
   for (int32_t i = 0; i < iLength; i++) {
+    int32_t iAbsolute = i + pTxtRun->iStart;
     if (pEngine) {
-      wch = pEngine->GetChar(i);
-      iCharSize = pEngine->GetWidthOfChar(i);
+      wch = pEngine->GetChar(iAbsolute);
+      iCharSize = pEngine->GetWidthOfChar(iAbsolute);
     } else {
       wch = *pStr++;
       iCharSize = *pWidths++;
diff --git a/xfa/fgas/layout/cfx_txtbreak.h b/xfa/fgas/layout/cfx_txtbreak.h
index b43fda0e2f..a0e034280b 100644
--- a/xfa/fgas/layout/cfx_txtbreak.h
+++ b/xfa/fgas/layout/cfx_txtbreak.h
@@ -42,6 +42,7 @@ struct FX_TXTRUN {
   CFDE_TextEditEngine* pEdtEngine;
   WideString wsStr;
   int32_t* pWidths;
+  int32_t iStart;
   int32_t iLength;
   RetainPtr<CFGAS_GEFont> pFont;
   float fFontSize;
-- 
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