python - In django prepopulated_fields = {"slug": ("title",)} doesn't show all words -

i using

prepopulated_fields = {"slug": ("title",)} 

in django admin area , when type words like

 first slug 

into title field

only

first-slug 

is outputted in slug field, , if delete "t"in title field

the slug field output

his-first-slug 

"is" , "the" won't show up

in slug field. why that? or better yet how can fix type in title field displayed in slug field

there filter in action prevents words ending in slug or url. can see source of here. makes sure don't end words or symbols in slug/url shouldn't there.

how fix it? change mentioned file in /django/contrib/admin/static/admin/js/urlify.py , should go.