Use wxString's empty() when checking if the string is (non-)empty throughout wx.

Instead of constructs such as if "( s.length() )" and "if (s.length() > 0)" use "if ( !s.empty() )" instead. Similarly for "if (s.length() == 0)" or "if ( s.IsNull() )", use "if ( s.empty() )".
No code changes intended except for a few instances where a construct like "if ( s.length() && wxFileExists(s) )" was changed to not check the length of the string and let wxFileExists handle such cases.



git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@66728 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/fs_arc.cpp

@@ -358,7 +358,7 @@ wxFSFile* wxArchiveFSHandler::OpenFile(
         right = rightPart.GetFullPath(wxPATH_UNIX);
     }
 
-    if (right.Length() && right.GetChar(0) == wxT('/')) right = right.Mid(1);
+    if (!right.empty() && right.GetChar(0) == wxT('/')) right = right.Mid(1);
 
     if (!m_cache)
         m_cache = new wxArchiveFSCache;