error handling for showing genresult

chunkymap-regen.py

@@ -68,18 +68,25 @@ def view_traceback():
 
 def print_file(path, indent=""):
     try:
+        if path is not None:
             if os.path.isfile(path):
+                line_count = 0
                 if indent is None:
                     indent = ""
                     ins = open(path, 'r')
                     line = True
                     while line:
                         line = ins.readline()
+                        line_count += 1
                         if line:
                             print(indent+line)
                     ins.close()
+                    if line_count==0:
+                        print(indent+"print_file WARNING: "+str(line_count)+" line(s) in '"+path+"'")
             else:
-            print (indent+"print_file: missing path")
+                print (indent+"print_file: file does not exist")
+        else:
+            print (indent+"print_file: path is None")
     except:
         print(indent+"print_file: could not finish")