Windows: GUI "Open" works

src/utils/execmd.cpp

@@ -153,7 +153,7 @@ public:
 };
 bool ExecCmd::Internal::o_useVfork = false;
 
-ExecCmd::ExecCmd()
+ExecCmd::ExecCmd(int)
 {
     m = new Internal();
     if (m)

src/utils/execmd.h

@@ -176,7 +176,14 @@ class ExecCmd {
      */
     bool requestChildExit();
 
-     ExecCmd();
+    enum ExFlags {EXF_NONE,
+                  // Only does anything on windows. Used when starting
+                  // a viewer. The default is to hide the window,
+                  // because it avoids windows appearing and
+                  // disappearing when executing stuff for previewing
+                  EXF_SHOWWINDOW = 1, 
+    };
+    ExecCmd(int flags = 0);
     ~ExecCmd();
 
     /**

src/utils/fstreewalk.cpp

@@ -361,6 +361,10 @@ FsTreeWalker::Status FsTreeWalker::iwalk(const string &top,
 	case EPERM:
 	case EACCES:
 	case ENOENT:
+#ifdef _WIN32
+            // We get this quite a lot, don't know why. To be checked.
+        case EINVAL:
+#endif
 	    goto out;
 	default:
 	    status = FtwError;