What I expected to happen:
After putting text into a book and quill, I could press escape to exit the book-and-quill GUI, and the text would be saved.

What actually happened:
After putting text into the book and quill, pressing escape instead of the "Done" button in the GUI would delete whatever text was in it, and revert back to whatever text had been typed before where the "Done" button was used.

Steps to recreate:
1. Type any text into a book and quill, and press the "Done" button in the GUI.
2. Re-open the book, and add onto the existing text, or create different text. This time, hit escape instead of the "Done" button to exit the GUI.
3. Re-open the book again, you should find that the text typed in step two has been reverted back to the text typed in step one.