Admin inlines not saving on "Save As New"

[pizzapanther]

I have an admin class that has 3 inlines (code below). When using the "Save as New" button the inlines are not saved under certain circumstances. The conditions that cause the problem are as follows. Usually one the inlines has no data which is expected. If you enter data for an inline that was not previously used then data is not saved on "Save as new". If there was data previously entered and you just change that inline then everything works fine. The data in the previously unused inlines is also not validated because you can enter bad data and no error messages are returned. So the data is just ignored altogether for some reason. Will attach some screen shots shortly.

class EPAdmin (admin.TabularInline):
  model = hp_models.EditorsPick
  extra = 5
  max_num = 5
  raw_id_fields = ('event', 'clist', 'news', 'place', 'best')
  can_delete = False
  readonly_fields = ('crop',)
  
  fieldsets = (
        (None, {
            'fields': ('label', 'event', 'clist', 'news', 'place', 'best', 'iorder', 'crop')
        }),)
        
class ThreadAdmin (admin.TabularInline):
  model = hp_models.Thread
  extra = 5
  max_num = 7
  raw_id_fields = ('event', 'clist', 'news', 'place', 'best')
  readonly_fields = ('crop',)
  
  fieldsets = (
        (None, {
            'fields': ('event', 'clist', 'news', 'place', 'best', 'iorder', 'crop')
        }),)
        
class ThreadPlusAdmin (admin.TabularInline):
  model = hp_models.ThreadPlus
  extra = 2
  max_num = 2
  raw_id_fields = ('event', 'clist', 'news', 'place', 'best')
  can_delete = False
  
  fieldsets = (
        (None, {
            'fields': ('event', 'clist', 'news', 'place', 'best', 'iorder')
        }),)
        
class EPModuleAdmin (admin.ModelAdmin):
  inlines = (EPAdmin, ThreadAdmin, ThreadPlusAdmin)
  list_filter = ('publish', 'modtype')
  list_display = ('publish', 'modtype', 'clone', 'preview')
  save_as = True
  raw_id_fields = ('thread_photo',)
  readonly_fields = ('thread_crop',)
  
  class Media:
    js = ("javascript/jquery/jquery-1.3.2.js", "rd/js/admin/genericmodule.js",)

[pizzapanther]

Initial Object

[pizzapanther]

Changes that were made highlighted in red

[pizzapanther]

Successful info saved in green and missing data in red and green

[Julien Phalip]

Thank you for the report. I'm pretty sure this is a dupe of #14938.