Cancelling filechange save doesn't properly clean up info from memory

Reproduction step:

• Import the attached XAR (careful: it will prevent to use properly Change Request)
• Create a new page with content "XX. Create"
• Edit the page, replace XX by 1, check "minor edit" and save as change request
• Go to the change request edit the changes
• Uncheck the minor edit checkbox and add a line "2. Edit"
• Click save -> an error should appear
• Add a new line "3. Edit" and check the minor edit box
• Click save

Expected result:

• The save should happen at that point and the page should contain:

  1. Create
  2. Edit
  3. Edit
  

Obtained result:

• The page can never be saved at that point, trying to save multiple times will change the content in memory: leaving the editor and then going back to the CR and trying again to edit the changes displays an editor with all the cumulated attempts to save