fix formatting for edge case with i18n

lib/money/money/formatting.rb

@@ -205,6 +205,7 @@ def format(*rules)
       rules = default_formatting_rules.merge(rules)
       rules = localize_formatting_rules(rules)
       rules = translate_formatting_rules(rules) if rules[:translate]
+      escaped_decimal_mark = Regexp.escape(decimal_mark)
 
       if fractional == 0
         if rules[:display_free].respond_to?(:to_str)
@@ -236,9 +237,9 @@ def format(*rules)
 
       # Inspiration: https://github.com/rails/rails/blob/16214d1108c31174c94503caced3855b0f6bad95/activesupport/lib/active_support/number_helper/number_to_rounded_converter.rb#L72-L79
       if rules[:drop_trailing_zeros]
-        escaped_decimal_mark = Regexp.escape(decimal_mark)
         formatted = formatted.sub(/(#{escaped_decimal_mark})(\d*[1-9])?0+\z/, '\1\2').sub(/#{escaped_decimal_mark}\z/, '')
       end
+      has_decimal_value = !!(formatted =~ /#{escaped_decimal_mark}/)
 
       thousands_separator_value = thousands_separator
       # Determine thousands_separator
@@ -275,7 +276,7 @@ def format(*rules)
         formatted="#{sign_before}#{sign}#{formatted}"
       end
 
-      apply_decimal_mark_from_rules(formatted, rules)
+      apply_decimal_mark_from_rules(formatted, rules) if has_decimal_value
 
       if rules[:with_currency]
         formatted << " "

spec/money/formatting_spec.rb

@@ -110,6 +110,13 @@
         expect(money.format(:translate => true)).to eq("CAD$0.00")
       end
     end
+
+    context "with overridden i18n settings" do
+      it "should respect explicit overriding of thousands_separator/delimiter when decimal_mark/separator collide and there’s no decimal component" do
+        expect(Money.new(300_000, 'ISK').format(:thousands_separator => ".", decimal_mark: ',')).to eq "kr300.000"
+        expect(Money.new(300_000, 'USD').format(:thousands_separator => ".", decimal_mark: ',', drop_trailing_zeros: true)).to eq "$3.000"
+      end
+    end
   end
 
   describe "#format" do