Match updated requirements

app/models/derived_variables/lettings_log_variables.rb

@@ -277,9 +277,6 @@ private
     if form.start_year_2024_or_later? && unittype_gn_changed? && unittype_gn_was == 2
       self.beds = nil
     end
-    if form.start_year_2026_or_later?
-      reset_partner_fields!
-    end
   end
 
   def get_totelder
@@ -333,7 +330,10 @@ private
   end
 
   def infer_at_most_one_relationship!
-    if partner_numbers.any?
+    new_partner_numbers = partner_numbers.select { |i| public_send("relat#{i}_changed?") }
+    if new_partner_numbers.any?
+      infer_only_partner!(new_partner_numbers.first)
+    elsif partner_numbers.any?
       infer_only_partner!(partner_numbers.first)
     end
   end
@@ -350,19 +350,6 @@ private
     end
   end
 
-  def reset_partner_fields!
-    person_count = hhmemb || 8
-    (2..person_count).each do |i|
-      next unless send("relat#{i}_changed?") && send("relat#{i}_was") == "P"
-
-      ((i + 1)..person_count).each do |j|
-        if self["relat#{j}"] == "X"
-          self["relat#{j}"] = nil
-        end
-      end
-    end
-  end
-
   def household_type
     return unless totelder && totadult && totchild
 

app/models/form.rb

@@ -108,7 +108,8 @@ class Form
 
     return :check_answers if next_page.nil?
     return next_page.id if next_page.routed_to?(log, current_user) &&
-      (!ignore_answered || next_page.has_unanswered_questions?(log))
+      (!ignore_answered || next_page.has_unanswered_questions?(log)) &&
+      !next_page.skip_page_in_form_flow?(log)
 
     next_page_id(next_page, log, current_user, ignore_answered:)
   end

app/models/form/lettings/pages/person_lead_partner.rb

@@ -18,14 +18,18 @@ class Form::Lettings::Pages::PersonLeadPartner < ::Form::Page
             "operator" => ">=",
             "operand" => 16,
           },
-          **(2...@person_index).map { |i| ["relat#{i}", { "operator" => "!=", "operand" => "P" }] }.to_h,
         },
-        { "details_known_#{@person_index}" => 0,
+        {
+          "details_known_#{@person_index}" => 0,
           "age#{@person_index}" => nil,
-          **(2...@person_index).map { |i| ["relat#{i}", { "operator" => "!=", "operand" => "P" }] }.to_h },
+        },
       ]
     else
       [{ "details_known_#{@person_index}" => 0 }]
     end
   end
+
+  def skip_page_in_form_flow?(log)
+    log.is_another_person_partner?(@person_index)
+  end
 end

app/models/form/lettings/questions/person_partner.rb

@@ -36,14 +36,6 @@ class Form::Lettings::Questions::PersonPartner < ::Form::Question
   end
 
   def derived?(log)
-    form.start_year_2026_or_later? && log.is_partner_inferred?(@person_index)
-  end
-
-  def hidden_in_check_answers?(log, _current_user = nil)
-    if form.start_year_2026_or_later?
-      log.is_an_earlier_person_partner(@person_index)
-    else
-      false
-    end
+    form.start_year_2026_or_later? && log.is_person_under_16(@person_index)
   end
 end

app/models/form/page.rb

@@ -55,6 +55,10 @@ class Form::Page
 
   def skip_href(log = nil); end
 
+  def skip_page_in_form_flow?(_log)
+    false
+  end
+
 private
 
   def conditional_question_ids

app/models/lettings_log.rb

@@ -407,16 +407,12 @@ class LettingsLog < Log
     unittype_gn_changed? && unittype_gn_was == 2
   end
 
-  def is_partner_inferred?(person_index)
-    is_person_under_16(person_index) || is_an_earlier_person_partner(person_index)
-  end
-
   def is_person_under_16(person_index)
     public_send("age#{person_index}") && public_send("age#{person_index}") < 16
   end
 
-  def is_an_earlier_person_partner(person_index)
-    (2...person_index).any? do |i|
+  def is_another_person_partner?(person_index)
+    (2..8).reject { |i| i == person_index }.any? do |i|
       public_send("relat#{i}") == "P"
     end
   end