Do not crash if problem to access MC clipboard

docs/notework.txt

@@ -12,6 +12,8 @@ ______________________________________________________________________
                Notes for GoldED+ 1.1.5, /snapshot/
 ______________________________________________________________________
 
+- Do not crash if problem to access MC clipboard (Linux specific).
+
 - To fix problem with related pathname in NODEPATH the Goldnode will
   write only filename in .gxl file. Most users should not notice this
   change at all.

goldlib/gall/gutlunix.cpp

@@ -105,6 +105,8 @@ char* g_get_clip_text(void) {
   std::string clipfile = CLIPFILE;
   strschg_environ(clipfile);
   size_t size = GetFilesize(clipfile.c_str());
+
+  if(size != -1) {
     char *text = (char *)throw_malloc(size+1);
     *text = NUL;
 
@@ -114,6 +116,7 @@ char* g_get_clip_text(void) {
       text[size] = NUL;
       fclose(f);
     }
+  }
 
   return text;
 }