Created attachment 57567 [details]
Document with repeated imports of list styles with overwrite set

Problem description: When importing a custom bullet/numbering list with character style set to default Bullet/Numbering symbols, LibO creates new styles for each import, rather than using the already established ones. If you have a custom character style associated with it, it imports those correctly. If you reimport again, it creates duplicate character styles with altered anmes (adding _20 and _5f in various combinations)

Steps to reproduce:
1. create a document with a custom list/numbering with character type set to "Bullets" or "Numbering Symbols"
2. create a new document
3. import styles from old document

Current behavior: creates new character style called Bullets_20 or Numbering_20_Symbols

Expected behavior: Since using the default style for Bullets/Numbering Symbols, it would correctly set the style to those and not create new styles.

Platform (if different from the browser): 
              
Browser: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:10.0.2) Gecko/20100101 Firefox/10.0.2