fix `number_to_percentage` with `Float::NAN`, `Float::INFINITY`.

Closes #14405.

This is a follow-up to 9e997e90 to restore
the documented behavior.

actionview/CHANGELOG.md

+*   `number_to_percentage` does not crash with `Float::NAN` or `Float::INFINITY`
+    as input.
+
+    Fixes #14405.
+
+    *Yves Senn*
+
 *   Add `include_hidden` option to `collection_check_boxes` helper.
 
     *Vasiliy Ermolovich*

actionview/test/template/number_helper_test.rb

@@ -32,6 +32,9 @@ def test_number_to_percentage
     assert_equal "100%", number_to_percentage(100, precision: 0)
     assert_equal "123.4%", number_to_percentage(123.400, precision: 3, strip_insignificant_zeros: true)
     assert_equal "1.000,000%", number_to_percentage(1000, delimiter: ".", separator: ",")
+    assert_equal "98a%", number_to_percentage("98a")
+    assert_equal "NaN%", number_to_percentage(Float::NAN)
+    assert_equal "Inf%", number_to_percentage(Float::INFINITY)
   end
 
   def test_number_with_delimiter

activesupport/lib/active_support/number_helper/number_to_rounded_converter.rb

@@ -32,8 +32,7 @@ def convert
         end
 
         formatted_string =
-          case rounded_number
-          when BigDecimal
+          if BigDecimal === rounded_number && rounded_number.finite?
             s = rounded_number.to_s('F') + '0'*precision
             a, b = s.split('.', 2)
             a + '.' + b[0, precision]

activesupport/test/number_helper_test.rb

@@ -79,6 +79,9 @@ def test_number_to_percentage
           assert_equal("123.4%", number_helper.number_to_percentage(123.400, :precision => 3, :strip_insignificant_zeros => true))
           assert_equal("1.000,000%", number_helper.number_to_percentage(1000, :delimiter => '.', :separator => ','))
           assert_equal("1000.000  %", number_helper.number_to_percentage(1000, :format => "%n  %"))
+          assert_equal("98a%", number_helper.number_to_percentage("98a"))
+          assert_equal("NaN%", number_helper.number_to_percentage(Float::NAN))
+          assert_equal("Inf%", number_helper.number_to_percentage(Float::INFINITY))
         end
       end