fixed BUG-8, no genres for a sub book addition loses parent details

BUGs

@@ -8,5 +8,3 @@ BUG-6:		author,series, etc. do not have explicit ordering like sub-books... sort
 			- add/remove authors, and after save they are ordered by author.id, not order of addition (prob. needs book_author_link to have an auth_num)
 
 BUG-7:		if you remove a series from a book, it won't appear in the series drop-down if it is the first 'missing' book in that series -- either reset the list, or show all series always?
-
-BUG-8:		if you add a sub-book, then fail to validate (say no genre), then it takes you back, you click a genre (BUT it has lost th eparent association), so it adds a book, not a sub-book

main.py

@@ -385,6 +385,7 @@ def new_book():
             parent=request.form['add_sub_parent_id']
             book = Book.query.get(parent)
             bb=QuickParentBook()
+            bb.parent=[]
             bb.parent.append( { 'id': parent, 'title': book.title } )
             form.publisher.default = book.publisher
             form.owned.default = book.owned
@@ -418,7 +419,13 @@ def new_book():
                 message = "{}<br>genre=book has to have a genre selected".format( message )
             print( "ERROR: Failed to create book: {}".format(message) )
             book = Book( title=request.form["title"], owned=request.form['owned'], covertype=request.form['covertype'], condition=request.form['condition'], publisher=request.form['publisher'], year_published=request.form['year_published'], rating=request.form['rating'], notes=request.form['notes'], blurb=request.form['blurb'], genre=book_genres, author=book_authors )
-            return render_template("book.html", page_title=page_title, b=None, books=book, book_form=form, author_list=author_list, genre_list=genre_list, alert=alert, message=message, poss_series_list=ListOfSeriesWithMissingBooks() )
+            if 'parent_id' in request.form:
+                bb=QuickParentBook()
+                bb.parent=[]
+                bb.parent.append( { 'id': request.form['parent_id'], 'title': request.form['parent_title'] } )
+            else:
+                bb=None
+            return render_template("book.html", page_title=page_title, b=bb, books=book, book_form=form, author_list=author_list, genre_list=genre_list, alert=alert, message=message, poss_series_list=ListOfSeriesWithMissingBooks() )
     else:
         return render_template("book.html", page_title=page_title, b=None, books=None, book_form=form, author_list=author_list, genre_list=genre_list, alert="success", message="", poss_series_list=ListOfSeriesWithMissingBooks() )
 

templates/book.html

@@ -139,6 +139,7 @@ function AddAuthorToBook(num) {
 						</button>
 					</div>
 					<input type="hidden" name="parent_id" value="{{b.parent[0].id}}">
+					<input type="hidden" name="parent_title" value="{{b.parent[0].title}}">
 				</div>
 			{% endif %}
 			{% for key in keys %}