Destroy window before cleaning up combobox

fpdfsdk/formfiller/cffl_combobox.cpp

Index: fpdfsdk/formfiller/cffl_combobox.cpp
diff --git a/fpdfsdk/formfiller/cffl_combobox.cpp b/fpdfsdk/formfiller/cffl_combobox.cpp
index 35591cff74215cf68a46fbcf02c187925b7214da..42405cbb223bea9d002128da321c4ea64b527597 100644
--- a/fpdfsdk/formfiller/cffl_combobox.cpp
+++ b/fpdfsdk/formfiller/cffl_combobox.cpp
@@ -24,6 +24,14 @@ CFFL_ComboBox::CFFL_ComboBox(CPDFDoc_Environment* pApp, CPDFSDK_Annot* pAnnot)
 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;
 }