Destroy window before cleaning up combobox

fpdfsdk/formfiller/cffl_combobox.cpp

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #include "fpdfsdk/formfiller/cffl_combobox.h"
 
 #include "fpdfsdk/formfiller/cba_fontmap.h"
 #include "fpdfsdk/formfiller/cffl_formfiller.h"
 #include "fpdfsdk/formfiller/cffl_iformfiller.h"
 #include "fpdfsdk/include/cpdfsdk_widget.h"
 #include "fpdfsdk/include/fsdk_common.h"
 #include "fpdfsdk/include/fsdk_mgr.h"
 #include "fpdfsdk/pdfwindow/PWL_ComboBox.h"
 
 CFFL_ComboBox::CFFL_ComboBox(CPDFDoc_Environment* pApp, CPDFSDK_Annot* pAnnot)
     : CFFL_FormFiller(pApp, pAnnot), m_pFontMap(nullptr) {
   m_State.nIndex = 0;
   m_State.nStart = 0;
   m_State.nEnd = 0;
 }
 
 CFFL_ComboBox::~CFFL_ComboBox() {
   for (const auto& it : m_Maps)
     it.second->InvalidateFocusHandler(this);
+
+  // The combo box must destroy the window before it frees the font map because
+  // when the window destroys the PWL_Edit the edit will update the selection
+  // which requires getting the font data from the font map.
+  //
+  // The font map should be stored somewhere more appropriate so it will live
+  // until the PWL_Edit is done with it. pdfium:566

[Wei Li, 2016/08/22 19:26:56]

Does this only happen to ComboBox? How about ListBox, TextField and such?

[dsinclair, 2016/08/22 19:32:08]

It doesn't look like ListBox has this issue as it doesn't do anything with
SetFocus. If the TextField is backed by a PWL_Edit, it's possible it will have
an issue, need to try to construct a test case to find out of there is a
problem. Other widgets, it will depend on if they have a PWL_Edit and what
happens when you call the SetFocus method.

+  DestroyWindows();
   delete m_pFontMap;
 }
 
 PWL_CREATEPARAM CFFL_ComboBox::GetCreateParam() {
   PWL_CREATEPARAM cp = CFFL_FormFiller::GetCreateParam();
 
   int nFlags = m_pWidget->GetFieldFlags();
   if (nFlags & FIELDFLAG_EDIT) {
     cp.dwFlags |= PCBS_ALLOWCUSTOMTEXT;
   }
@@ skipping 247 matching lines @@
   if (nExport >= 0) {
     if (CPDF_FormField* pFormField = m_pWidget->GetFormField()) {
       swRet = pFormField->GetOptionValue(nExport);
       if (swRet.IsEmpty())
         swRet = pFormField->GetOptionLabel(nExport);
     }
   }
 
   return swRet;
 }