Implement CPWL_ComboBox::OnDestroy() to manage unowned pointers.

CPWL_ComboBox's unowned pointers to other CPWL_Wnds need to be released
at the right time. Also release the unowned pointer for CPWL_Wnd's
vertical scroll bar at the right time.

BUG=729041

Change-Id: I06a1da35fcb18dae8faf9cd4fbc0b75d38f115b0
Reviewed-on: https://pdfium-review.googlesource.com/6418
Commit-Queue: dsinclair <dsinclair@chromium.org>
Reviewed-by: dsinclair <dsinclair@chromium.org>

1 files changed, 12 insertions, 8 deletions

diff --git a/fpdfsdk/pdfwindow/cpwl_combo_box.cpp b/fpdfsdk/pdfwindow/cpwl_combo_box.cpp
index 42786806d0..b69f98906e 100644
--- a/fpdfsdk/pdfwindow/cpwl_combo_box.cpp
+++ b/fpdfsdk/pdfwindow/cpwl_combo_box.cpp
@@ -182,14 +182,7 @@ bool CPWL_CBButton::OnLButtonUp(const CFX_PointF& point, uint32_t nFlag) {
   return true;
 }
 
-CPWL_ComboBox::CPWL_ComboBox()
-    : m_pEdit(nullptr),
-      m_pButton(nullptr),
-      m_pList(nullptr),
-      m_bPopup(false),
-      m_bBottom(true),
-      m_nSelectItem(-1),
-      m_pFillerNotify(nullptr) {}
+CPWL_ComboBox::CPWL_ComboBox() {}
 
 CPWL_ComboBox::~CPWL_ComboBox() {}
 
@@ -202,6 +195,17 @@ void CPWL_ComboBox::OnCreate(PWL_CREATEPARAM& cp) {
   cp.dwFlags &= ~PWS_VSCROLL;
 }
 
+void CPWL_ComboBox::OnDestroy() {
+  // Until cleanup takes place in the virtual destructor for CPWL_Wnd
+  // subclasses, implement the virtual OnDestroy method that does the
+  // cleanup first, then invokes the superclass OnDestroy ... gee,
+  // like a dtor would.
+  m_pList.Release();
+  m_pButton.Release();
+  m_pEdit.Release();
+  CPWL_Wnd::OnDestroy();
+}
+
 void CPWL_ComboBox::SetFocus() {
   if (m_pEdit)
     m_pEdit->SetFocus();