Merge branch 'cotaskmemptr' of https://github.com/PBfordev/wxWidgets

Add wxCoTaskMemPtr and use it instead of manual calls to
::CoTaskMemFree().

See https://github.com/wxWidgets/wxWidgets/pull/1890

include/wx/msw/private/cotaskmemptr.h

@@ -0,0 +1,85 @@
+///////////////////////////////////////////////////////////////////////////////
+// Name:        wx/msw/private/cotaskmemptr.h
+// Purpose:     RAII class for pointers to be freed with ::CoTaskMemFree().
+// Author:      PB
+// Created:     2020-06-09
+// Copyright:   (c) 2020 wxWidgets team
+// Licence:     wxWindows licence
+///////////////////////////////////////////////////////////////////////////////
+
+#ifndef _WX_MSW_PRIVATE_COTASKMEMPTR_H_
+#define _WX_MSW_PRIVATE_COTASKMEMPTR_H_
+
+// needed for ::CoTaskMem{Alloc|Free}()
+#include "wx/msw/wrapwin.h"
+
+// ----------------------------------------------------------------------------
+// wxCoTaskMemPtr: A barebone RAII class for pointers to be freed with ::CoTaskMemFree().
+// ----------------------------------------------------------------------------
+
+template <class T>
+class wxCoTaskMemPtr
+{
+public:
+    typedef T element_type;
+
+    wxCoTaskMemPtr()
+        : m_ptr(NULL)
+    {}
+
+    explicit wxCoTaskMemPtr(T* ptr)
+        : m_ptr(ptr)
+    {}
+
+    // Uses ::CoTaskMemAlloc() to allocate size bytes.
+    explicit wxCoTaskMemPtr(size_t size)
+        : m_ptr(static_cast<T*>(::CoTaskMemAlloc(size)))
+    {}
+
+    ~wxCoTaskMemPtr()
+    {
+        ::CoTaskMemFree(m_ptr);
+    }
+
+    void reset(T* ptr = NULL)
+    {
+        if ( m_ptr != ptr )
+        {
+            ::CoTaskMemFree(m_ptr);
+            m_ptr = ptr;
+        }
+    }
+
+    operator T*() const
+    {
+        return m_ptr;
+    }
+
+    // It would be better to forbid direct access completely but we do need it,
+    // so provide it but it can only be used to initialize the pointer,
+    // not to modify an existing one.
+    T** operator&()
+    {
+        wxASSERT_MSG(!m_ptr,
+                     wxS("Can't get direct access to initialized pointer"));
+
+        return &m_ptr;
+    }
+
+    // Gives up the ownership of the pointer,
+    // making the caller responsible for freeing it.
+    T* release()
+    {
+        T* ptr(m_ptr);
+
+        m_ptr = NULL;
+        return ptr;
+    }
+
+private:
+    T* m_ptr;
+
+    wxDECLARE_NO_COPY_TEMPLATE_CLASS(wxCoTaskMemPtr, T);
+};
+
+#endif // _WX_MSW_PRIVATE_COTASKMEMPTR_H_

src/msw/stdpaths.cpp

@@ -36,6 +36,7 @@
 
 #include "wx/msw/private.h"
 #include "wx/msw/wrapshl.h"
+#include "wx/msw/private/cotaskmemptr.h"
 #include <initguid.h>
 
 // ----------------------------------------------------------------------------
@@ -171,12 +172,11 @@ wxString wxStandardPaths::DoGetKnownFolder(const GUID& rfid)
 
     if ( gs_shellFuncs.pSHGetKnownFolderPath )
     {
-        PWSTR pDir;
+        wxCoTaskMemPtr<wchar_t> pDir;
         HRESULT hr = gs_shellFuncs.pSHGetKnownFolderPath(rfid, 0, 0, &pDir);
         if ( SUCCEEDED(hr) )
         {
             dir = pDir;
-            CoTaskMemFree(pDir);
         }
     }
 

src/msw/taskbarbutton.cpp

@@ -29,6 +29,7 @@
 #include "wx/msw/taskbarbutton.h"
 #include "wx/scopedptr.h"
 #include "wx/msw/private/comptr.h"
+#include "wx/msw/private/cotaskmemptr.h"
 
 #include <shlwapi.h>
 #include <initguid.h>
@@ -498,10 +499,9 @@ wxTaskBarJumpListItem* GetItemFromIShellItem(IShellItem *shellItem)
     wxTaskBarJumpListItem *item =
         new wxTaskBarJumpListItem(NULL, wxTASKBAR_JUMP_LIST_DESTINATION);
 
-    wchar_t *name;
+    wxCoTaskMemPtr<wchar_t> name;
     shellItem->GetDisplayName(SIGDN_FILESYSPATH, &name);
     item->SetFilePath(wxString(name));
-    CoTaskMemFree(name);
     return item;
 }
 

src/msw/textentry.cpp

@@ -37,6 +37,7 @@
 
 #include "wx/msw/private.h"
 #include "wx/msw/private/winstyle.h"
+#include "wx/msw/private/cotaskmemptr.h"
 
 #if wxUSE_UXTHEME
     #include "wx/msw/uxtheme.h"
@@ -207,13 +208,13 @@ public:
 
             const wxWX2WCbuf wcbuf = s.wc_str();
             const size_t size = (wcslen(wcbuf) + 1)*sizeof(wchar_t);
-            void *olestr = CoTaskMemAlloc(size);
+            wxCoTaskMemPtr<wchar_t> olestr(size);
+
             if ( !olestr )
                 return E_OUTOFMEMORY;
 
             memcpy(olestr, wcbuf, size);
-
-            *rgelt++ = static_cast<LPOLESTR>(olestr);
+            *rgelt++ = olestr.release();
 
             ++(*pceltFetched);
         }

src/msw/webview_edge.cpp

@@ -26,6 +26,7 @@
 #include "wx/private/jsscriptwrapper.h"
 #include "wx/private/json.h"
 #include "wx/msw/private.h"
+#include "wx/msw/private/cotaskmemptr.h"
 #include "wx/msw/private/webview_edge.h"
 
 #include <wrl/event.h>
@@ -124,16 +125,10 @@ bool wxWebViewEdgeImpl::Initialize()
         return false;
 
     // Check if a Edge browser can be found by the loader DLL
-    LPWSTR versionStr;
+    wxCoTaskMemPtr<wchar_t> versionStr;
     HRESULT hr = wxGetAvailableCoreWebView2BrowserVersionString(NULL, &versionStr);
-    if (SUCCEEDED(hr))
-    {
-        if (versionStr)
-        {
-            CoTaskMemFree(versionStr);
-            return true;
-        }
-    }
+    if (SUCCEEDED(hr) && versionStr)
+        return true;
     else
         wxLogApiError("GetCoreWebView2BrowserVersionInfo", hr);
 
@@ -161,12 +156,10 @@ HRESULT wxWebViewEdgeImpl::OnNavigationStarting(ICoreWebView2* WXUNUSED(sender),
 {
     m_isBusy = true;
     wxString evtURL;
-    LPWSTR uri;
+    wxCoTaskMemPtr<wchar_t> uri;
     if (SUCCEEDED(args->get_Uri(&uri)))
-    {
         evtURL = wxString(uri);
-        CoTaskMemFree(uri);
-    }
+
     wxWebViewEvent event(wxEVT_WEBVIEW_NAVIGATING, m_ctrl->GetId(), evtURL, wxString());
     event.SetEventObject(m_ctrl);
     m_ctrl->HandleWindowEvent(event);
@@ -245,13 +238,10 @@ HRESULT wxWebViewEdgeImpl::OnNavigationCompleted(ICoreWebView2* WXUNUSED(sender)
 
 HRESULT wxWebViewEdgeImpl::OnNewWindowRequested(ICoreWebView2* WXUNUSED(sender), ICoreWebView2NewWindowRequestedEventArgs* args)
 {
-    LPWSTR uri;
+    wxCoTaskMemPtr<wchar_t> uri;
     wxString evtURL;
     if (SUCCEEDED(args->get_Uri(&uri)))
-    {
         evtURL = wxString(uri);
-        CoTaskMemFree(uri);
-    }
     wxWebViewNavigationActionFlags navFlags = wxWEBVIEW_NAV_ACTION_OTHER;
 
     BOOL isUserInitiated;
@@ -519,26 +509,18 @@ bool wxWebViewEdge::IsBusy() const
 
 wxString wxWebViewEdge::GetCurrentURL() const
 {
-    LPWSTR uri;
+    wxCoTaskMemPtr<wchar_t> uri;
     if (m_impl->m_webView && SUCCEEDED(m_impl->m_webView->get_Source(&uri)))
-    {
-        wxString uriStr(uri);
-        CoTaskMemFree(uri);
-        return uriStr;
-    }
+        return wxString(uri);
     else
         return wxString();
 }
 
 wxString wxWebViewEdge::GetCurrentTitle() const
 {
-    LPWSTR title;
+    wxCoTaskMemPtr<wchar_t> title;
     if (m_impl->m_webView && SUCCEEDED(m_impl->m_webView->get_DocumentTitle(&title)))
-    {
-        wxString titleStr(title);
-        CoTaskMemFree(title);
-        return titleStr;
-    }
+        return wxString(title);
     else
         return wxString();
 }