handle when file does not exist before opening it as a document

Author: robertbasic

pugdebug/pugdebug.py

@@ -9,6 +9,8 @@
 
 __author__ = "robertbasic"
 
+import os
+
 from PyQt5.QtCore import QObject
 from PyQt5.QtWidgets import QErrorMessage
 
@@ -201,10 +203,22 @@ def open_document(self, path, map_paths=True):
         tab.
 
         If the document is already open, focus the tab with that document.
+
+        If the path of the document should be mapped, and the file can't
+        be found after mapping, show an error message and stop the debugging
+        session.
         """
 
         path = self.__get_path_mapped_to_local(path, map_paths)
 
+        if path is False:
+            self.handle_error(
+                "File does not exist after mapping. "
+                "Is the path map correct?"
+            )
+            self.stop_debug()
+            return
+
         if not self.documents.is_document_open(path):
             document_model = self.documents.open_document(path)
 
@@ -637,6 +651,9 @@ def __get_path_mapped_to_local(self, path, map_paths=True):
             path = path[len(path_map):]
             path = "%s%s" % (self.file_browser.model().rootPath(), path)
 
+            if not os.path.isfile(path):
+                return False
+
         return path
 
     def __get_path_mapped_to_remote(self, path):