[enh] Allow to define another attribute as primary mail source

config/locales/server.en.yml

@@ -11,3 +11,4 @@ en:
     ldap_bind_dn: "LDAP bind dn (needed if LDAP server does not allow anonymous binding)"
     ldap_password:  "LDAP bind password (needed if LDAP server does not allow anonymous binding)"
     ldap_filter:  "LDAP filter (for group based authentication)"
+    ldap_email:  "Mail attribute to bind in priority to discourse primary mail"

config/settings.yml

@@ -24,3 +24,5 @@ plugins:
     secret: true
   ldap_filter:
     default: ''
+  ldap_email:
+    default: 'email'

lib/ldap_user.rb

@@ -7,6 +7,14 @@ def initialize (auth_info)
     @email = auth_info[:email]
     @username = auth_info[:nickname]
     @user = SiteSetting.ldap_lookup_users_by == 'username' ? User.find_by_username(@username) : User.find_by_email(@email)
+    primary_email = @user.user_emails.find_by(email: @user.email)
+    if primary_email.present?
+      primary_email.update!(email: @email)
+    else
+      @user.user_emails.update_all(primary: false)
+      @user.user_emails.create!(email: @email, primary: true)
+    end
+    @user.reload
     create_user_groups(auth_info[:groups]) unless self.account_exists?
   end
 

plugin.rb

@@ -26,6 +26,16 @@ def enabled?
   end
 
   def after_authenticate(auth_options)
+    if SiteSetting.ldap_email != 'email'
+      if not auth_options.extra[:raw_info][SiteSetting.ldap_email].blank?
+        emails = Array(auth_options.extra[:raw_info][SiteSetting.ldap_email])
+          .select { |email| email.match?(/\A[^@\s]+@[^@\s]+\z/) }
+        if not emails.empty?
+          auth_options.info[:email] = emails.first()
+        end
+      end
+    end
+
     auth_result(auth_options.info)
   end