don't load comctl32.dll, just get the handle of the already loaded instance of it instead [backport of r56863 and r57405 from trunk] (closes #10203)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_8_BRANCH@58750 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/dynlib.h

@@ -76,6 +76,18 @@ enum wxDLFlags
     wxDL_NOSHARE    = 0x00000010,   // load new DLL, don't reuse already loaded
                                     // (only for wxPluginManager)
 
+    wxDL_QUIET      = 0x00000020,   // don't log an error if failed to load
+
+#if wxABI_VERSION >= 20810
+    // this flag is dangerous, for internal use of wxMSW only, don't use at all
+    // and especially don't use directly, use wxLoadedDLL instead if you really
+    // do need it
+    wxDL_GET_LOADED = 0x00000040,   // Win32 only: return handle of already
+                                    // loaded DLL or NULL otherwise; Unload()
+                                    // should not be called so don't forget to
+                                    // Detach() if you use this function
+#endif // wx 2.8.10+
+
     wxDL_DEFAULT    = wxDL_NOW      // default flags correspond to Win32
 };
 
@@ -309,6 +321,28 @@ protected:
     DECLARE_NO_COPY_CLASS(wxDynamicLibrary)
 };
 
+#if defined(__WXMSW__) && wxABI_VERSION >= 20810
+
+// ----------------------------------------------------------------------------
+// wxLoadedDLL is a MSW-only internal helper class allowing to dynamically bind
+// to a DLL already loaded into the project address space
+// ----------------------------------------------------------------------------
+
+class wxLoadedDLL : public wxDynamicLibrary
+{
+public:
+    wxLoadedDLL(const wxString& dllname)
+        : wxDynamicLibrary(dllname, wxDL_GET_LOADED | wxDL_VERBATIM | wxDL_QUIET)
+    {
+    }
+
+    ~wxLoadedDLL()
+    {
+        Detach();
+    }
+};
+
+#endif // __WXMSW__
 
 // ----------------------------------------------------------------------------
 // Interesting defines

src/msw/app.cpp

@@ -611,8 +611,16 @@ int wxApp::GetComCtl32Version()
         wxLogNull noLog;
 
 #if wxUSE_DYNLIB_CLASS
-        // do we have it?
-        wxDynamicLibrary dllComCtl32(_T("comctl32.dll"), wxDL_VERBATIM);
+        // we don't want to load comctl32.dll, it should be already loaded but,
+        // depending on the OS version and the presence of the manifest, it can
+        // be either v5 or v6 and instead of trying to guess it just get the
+        // handle of the already loaded version
+        wxLoadedDLL dllComCtl32(_T("comctl32.dll"));
+        if ( !dllComCtl32.IsLoaded() )
+        {
+            s_verComCtl32 = 0;
+            return 0;
+        }
 
         // if so, then we can check for the version
         if ( dllComCtl32.IsLoaded() )
@@ -668,7 +676,7 @@ int wxApp::GetComCtl32Version()
                 }
             }
         }
-#endif
+#endif // wxUSE_DYNLIB_CLASS
     }
 
     return s_verComCtl32;

src/msw/dlmsw.cpp

@@ -276,9 +276,11 @@ wxDllType wxDynamicLibrary::GetProgramHandle()
 
 /* static */
 wxDllType
-wxDynamicLibrary::RawLoad(const wxString& libname, int WXUNUSED(flags))
+wxDynamicLibrary::RawLoad(const wxString& libname, int flags)
 {
-    return ::LoadLibrary(libname);
+    return flags & wxDL_GET_LOADED
+            ? ::GetModuleHandle(libname)
+            : ::LoadLibrary(libname);
 }
 
 /* static */

src/msw/window.cpp

@@ -5180,9 +5180,9 @@ bool wxWindowMSW::HandleMouseMove(int x, int y, WXUINT flags)
             static bool s_initDone = false;
             if ( !s_initDone )
             {
-                wxLogNull noLog;
-
-                wxDynamicLibrary dllComCtl32(_T("comctl32.dll"), wxDL_VERBATIM);
+                // see comment in wxApp::GetComCtl32Version() explaining the
+                // use of wxLoadedDLL
+                wxLoadedDLL dllComCtl32(_T("comctl32.dll"));
                 if ( dllComCtl32.IsLoaded() )
                 {
                     s_pfn_TrackMouseEvent = (_TrackMouseEvent_t)
@@ -5190,10 +5190,6 @@ bool wxWindowMSW::HandleMouseMove(int x, int y, WXUINT flags)
                 }
 
                 s_initDone = true;
-
-                // notice that it's ok to unload comctl32.dll here as it won't
-                // be really unloaded, being still in use because we link to it
-                // statically too
             }
 
             if ( s_pfn_TrackMouseEvent )