Fix #1618

app/models/research/hal/author.rb

@@ -65,7 +65,8 @@ class Research::Hal::Author < ApplicationRecord
   end
 
   def import_research_hal_publications!
-    publications.hal.clear
+    # HAL author has only HAL publications
+    publications.clear
     # Do not overuse the API if no researcher is concerned
     return if researchers.none?
     Importers::Hal.import_publications_for_author(self).each do |publication|

app/models/university/person/with_research.rb

@@ -34,7 +34,7 @@ module University::Person::WithResearch
   end
 
   def import_research_hal_publications!
-    publications.hal.clear
+    publications.delete(publications.hal)
     hal_authors.each do |author|
       # TODO manage same researcher in different universities
       publications.concat author.import_research_hal_publications!