check whether unicows.dll works correctly instead of just crashing if we linked it...

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@35236 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

diff --git a/src/msw/main.cpp b/src/msw/main.cpp
index 8e0a07afc1a661e9d6f30b58d03d5fcb4e6a0dbb..ead91896d565e1b9cea4dd61c1ed0e05e72f4f12 100644 (file)
--- a/src/msw/main.cpp
+++ b/src/msw/main.cpp
@@ -253,19 +253,17 @@ int wxEntry(int& argc, wxChar **argv)
 
 #if wxUSE_GUI && defined(__WXMSW__)
 
-// ----------------------------------------------------------------------------
-// Windows-specific wxEntry
-// ----------------------------------------------------------------------------
+#if wxUSE_UNICODE && !defined(__WXWINCE__)
+    #define NEED_UNICODE_CHECK
+#endif
 
-WXDLLEXPORT int wxEntry(HINSTANCE hInstance,
-                        HINSTANCE WXUNUSED(hPrevInstance),
-                        wxCmdLineArgType WXUNUSED(pCmdLine),
-                        int nCmdShow)
+#ifdef NEED_UNICODE_CHECK
+
+// check whether Unicode is available
+static bool wxIsUnicodeAvailable()
 {
-    // the first thing to do is to check if we're trying to run an Unicode
-    // program under Win9x w/o MSLU emulation layer - if so, abort right now
-    // as it has no chance to work and has all chances to crash
-#if wxUSE_UNICODE && !defined(__WXWINCE__)
+    static const wchar_t *ERROR_STRING = L"wxWidgets Fatal Error";
+
     if ( wxGetOsVersion() != wxWINDOWS_NT )
     {
         // we need to be built with MSLU support
@@ -276,12 +274,14 @@ WXDLLEXPORT int wxEntry(HINSTANCE hInstance,
         ::MessageBox
         (
          NULL,
-         _T("This program uses Unicode and requires Windows NT/2000/XP.\n\nProgram aborted."),
-         _T("wxWidgets Fatal Error"),
+         L"This program uses Unicode and requires Windows NT/2000/XP.\n"
+         L"\n"
+         L"Program aborted.",
+         ERROR_STRING,
          MB_ICONERROR | MB_OK
         );
 
-        return -1;
+        return false;
 #endif // !wxUSE_UNICODE_MSLU
 
         // and the MSLU DLL must also be available
@@ -291,17 +291,62 @@ WXDLLEXPORT int wxEntry(HINSTANCE hInstance,
             ::MessageBox
             (
              NULL,
-             _T("This program uses Unicode and requires unicows.dll to work under current operating system.\n\nPlease install unicows.dll and relaunch the program."),
-             _T("wxWidgets Fatal Error"),
+             L"This program uses Unicode and requires unicows.dll to work "
+             L"under current operating system.\n"
+             L"\n"
+             L"Please install unicows.dll and relaunch the program.",
+             ERROR_STRING,
              MB_ICONERROR | MB_OK
             );
-            return -1;
+            return false;
         }
 
         // this is not really necessary but be tidy
         ::FreeLibrary(hmod);
+
+        // finally do the last check: has unicows.lib initialized correctly?
+        hmod = ::LoadLibraryW(L"unicows.dll");
+        if ( !hmod )
+        {
+            ::MessageBox
+            (
+             NULL,
+             L"This program uses Unicode but is not using unicows.dll\n"
+             L"correctly and so cannot work under current operating system.\n"
+             L"Please contact the program author for an updated version.\n"
+             L"\n"
+             L"Program aborted.",
+             ERROR_STRING,
+             MB_ICONERROR | MB_OK
+            );
+
+            return false;
+        }
+
+        ::FreeLibrary(hmod);
     }
-#endif // wxUSE_UNICODE && !wxUSE_UNICODE_MSLU
+
+    return true;
+}
+
+#endif // NEED_UNICODE_CHECK
+
+// ----------------------------------------------------------------------------
+// Windows-specific wxEntry
+// ----------------------------------------------------------------------------
+
+WXDLLEXPORT int wxEntry(HINSTANCE hInstance,
+                        HINSTANCE WXUNUSED(hPrevInstance),
+                        wxCmdLineArgType WXUNUSED(pCmdLine),
+                        int nCmdShow)
+{
+    // the first thing to do is to check if we're trying to run an Unicode
+    // program under Win9x w/o MSLU emulation layer - if so, abort right now
+    // as it has no chance to work and has all chances to crash
+#ifdef NEED_UNICODE_CHECK
+    if ( !wxIsUnicodeAvailable() )
+        return -1;
+#endif // NEED_UNICODE_CHECK
 
 
     // remember the parameters Windows gave us