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>

6 files changed, 26 insertions, 27 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();
diff --git a/fpdfsdk/pdfwindow/cpwl_combo_box.h b/fpdfsdk/pdfwindow/cpwl_combo_box.h
index 71bd1a9e1c..e814ca5d40 100644
--- a/fpdfsdk/pdfwindow/cpwl_combo_box.h
+++ b/fpdfsdk/pdfwindow/cpwl_combo_box.h
@@ -57,6 +57,7 @@ class CPWL_ComboBox : public CPWL_Wnd {
   // CPWL_Wnd:
   CFX_ByteString GetClassName() const override;
   void OnCreate(PWL_CREATEPARAM& cp) override;
+  void OnDestroy() override;
   bool OnKeyDown(uint16_t nChar, uint32_t nFlag) override;
   bool OnChar(uint16_t nChar, uint32_t nFlag) override;
   void OnNotify(CPWL_Wnd* pWnd,
@@ -97,9 +98,9 @@ class CPWL_ComboBox : public CPWL_Wnd {
   CFX_UnownedPtr<CPWL_CBButton> m_pButton;
   CFX_UnownedPtr<CPWL_CBListBox> m_pList;
   CFX_FloatRect m_rcOldWindow;
-  bool m_bPopup;
-  bool m_bBottom;
-  int32_t m_nSelectItem;
+  bool m_bPopup = false;
+  bool m_bBottom = true;
+  int32_t m_nSelectItem = -1;
   CFX_UnownedPtr<IPWL_Filler_Notify> m_pFillerNotify;
   CFX_UnownedPtr<CFFL_FormFiller> m_pFormFiller;
 };
diff --git a/fpdfsdk/pdfwindow/cpwl_edit.cpp b/fpdfsdk/pdfwindow/cpwl_edit.cpp
index fd785e0603..d807f32c34 100644
--- a/fpdfsdk/pdfwindow/cpwl_edit.cpp
+++ b/fpdfsdk/pdfwindow/cpwl_edit.cpp
@@ -39,8 +39,6 @@ CFX_ByteString CPWL_Edit::GetClassName() const {
   return PWL_CLASSNAME_EDIT;
 }
 
-void CPWL_Edit::OnDestroy() {}
-
 void CPWL_Edit::SetText(const CFX_WideString& csText) {
   CFX_WideString swText = csText;
   if (!HasFlag(PES_RICH)) {
diff --git a/fpdfsdk/pdfwindow/cpwl_edit.h b/fpdfsdk/pdfwindow/cpwl_edit.h
index 1ed01b9657..5e82a5746b 100644
--- a/fpdfsdk/pdfwindow/cpwl_edit.h
+++ b/fpdfsdk/pdfwindow/cpwl_edit.h
@@ -48,7 +48,6 @@ class CPWL_Edit : public CPWL_EditCtrl {
 
   // CPWL_EditCtrl
   CFX_ByteString GetClassName() const override;
-  void OnDestroy() override;
   void OnCreated() override;
   void RePosChildWnd() override;
   CFX_FloatRect GetClientRect() const override;
diff --git a/fpdfsdk/pdfwindow/cpwl_wnd.cpp b/fpdfsdk/pdfwindow/cpwl_wnd.cpp
index 57e2643220..90a79305eb 100644
--- a/fpdfsdk/pdfwindow/cpwl_wnd.cpp
+++ b/fpdfsdk/pdfwindow/cpwl_wnd.cpp
@@ -186,6 +186,7 @@ void CPWL_Wnd::Destroy() {
   KillFocus();
   OnDestroy();
   if (m_bCreated) {
+    m_pVScrollBar = nullptr;
     for (auto it = m_Children.rbegin(); it != m_Children.rend(); ++it) {
       if (CPWL_Wnd* pChild = *it) {
         *it = nullptr;
@@ -201,7 +202,6 @@ void CPWL_Wnd::Destroy() {
   DestroyMsgControl();
   m_sPrivateParam.Reset();
   m_Children.clear();
-  m_pVScrollBar = nullptr;
 }
 
 void CPWL_Wnd::Move(const CFX_FloatRect& rcNew, bool bReset, bool bRefresh) {
diff --git a/fpdfsdk/pdfwindow/cpwl_wnd.h b/fpdfsdk/pdfwindow/cpwl_wnd.h
index 86b0c66272..e7a4e23c38 100644
--- a/fpdfsdk/pdfwindow/cpwl_wnd.h
+++ b/fpdfsdk/pdfwindow/cpwl_wnd.h
@@ -73,18 +73,15 @@ class IPWL_Provider;
 #define PRES_TEXTOVERFLOW 0x0400L
 
 // notification messages
-#define PNM_ADDCHILD 0x00000000L
-#define PNM_REMOVECHILD 0x00000001L
-#define PNM_SETSCROLLINFO 0x00000002L
-#define PNM_SETSCROLLPOS 0x00000003L
-#define PNM_SCROLLWINDOW 0x00000004L
-#define PNM_LBUTTONDOWN 0x00000005L
-#define PNM_LBUTTONUP 0x00000006L
-#define PNM_MOUSEMOVE 0x00000007L
-#define PNM_NOTERESET 0x00000008L
-#define PNM_SETCARETINFO 0x00000009L
-#define PNM_SELCHANGED 0x0000000AL
-#define PNM_NOTEEDITCHANGED 0x0000000BL
+#define PNM_ADDCHILD 0
+#define PNM_REMOVECHILD 1
+#define PNM_SETSCROLLINFO 2
+#define PNM_SETSCROLLPOS 3
+#define PNM_SCROLLWINDOW 4
+#define PNM_LBUTTONDOWN 5
+#define PNM_LBUTTONUP 6
+#define PNM_MOUSEMOVE 7
+#define PNM_SETCARETINFO 8
 
 #define PWL_CLASSNAME_EDIT "CPWL_Edit"