moved AppendAppName() from MSW to common code; modified it to not double the trailing slash, if any

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@30026 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/stdpbase.cpp

@@ -24,6 +24,11 @@
     #pragma hdrstop
 #endif
 
+#ifndef WX_PRECOMP
+    #include "wx/app.h"
+#endif //WX_PRECOMP
+
+#include "wx/filename.h"
 #include "wx/stdpaths.h"
 
 // ----------------------------------------------------------------------------
@@ -57,3 +62,25 @@ wxString wxStandardPathsBase::GetUserLocalDataDir() const
     return GetUserDataDir();
 }
 
+/* static */
+wxString wxStandardPathsBase::AppendAppName(const wxString& dir)
+{
+    wxString subdir(dir);
+
+    // empty string indicates that an error has occured, don't touch it then
+    if ( !subdir.empty() )
+    {
+        const wxString appname = wxTheApp->GetAppName();
+        if ( !appname.empty() )
+        {
+            const wxChar ch = *(subdir.end() - 1);
+            if ( !wxFileName::IsPathSeparator(ch) && ch != _T('.') )
+                subdir += wxFileName::GetPathSeparator();
+
+            subdir += appname;
+        }
+    }
+
+    return subdir;
+}
+