Fix AcroForm Javascript actions to gracefully handle Infinity/NaN

CHANGELOG.md

@@ -1,3 +1,11 @@
+## Unreleased
+
+### Fixed
+
+* AcroForm Javascript actions to gracefully handle the special values infinity
+  and NaN
+
+
 ## 1.1.1 - 2025-01-08
 
 ### Fixed

lib/hexapdf/type/acro_form/java_script_actions.rb

@@ -496,7 +496,7 @@ def calculate(form, calculate_action)
                    else
                      nil
                    end
-          result && (result == result.truncate ? result.to_i.to_s : result.to_s)
+          result && (result.finite? && result == result.truncate ? result.to_i.to_s : result.to_s)
         end
 
         AF_SIMPLE_CALCULATE_MAPPING = { #:nodoc:
@@ -613,7 +613,13 @@ def run_simplified_field_notation(form, action_string)
 
         # Returns the numeric value of the string, interpreting comma as point.
         def af_make_number(value)
-          value.to_s.tr(',', '.').to_f
+          if value.match?(/(?:[+-])?Inf(?:inity)?/i)
+            value.start_with?('-') ? -Float::INFINITY : Float::INFINITY
+          elsif value.match?(/NaN/i)
+            Float::NAN
+          else
+            value.to_s.tr(',', '.').to_f
+          end
         end
 
         # Formats the numeric value according to the format string and separator style.

test/hexapdf/type/acro_form/test_java_script_actions.rb

@@ -82,6 +82,15 @@ def assert_format(arg_string, result_value, result_color)
         assert_equal('1.234,57', value)
       end
 
+      it "works with the special Infinity and NaN values" do
+        @value = 'Infinity'
+        assert_format('2, 2, 0, 0, "", false', "Inf", "black")
+        @value = '-Infinity'
+        assert_format('2, 2, 0, 0, "", false', "-Inf", "black")
+        @value = 'Nan'
+        assert_format('2, 2, 0, 0, "", false', "NaN", "black")
+      end
+
       it "does nothing to the value if the JavaScript method could not be determined " do
         assert_format('2, 3, 0, 0, " E", false, a', "1234567.898765", nil)
       end
@@ -244,6 +253,13 @@ def assert_calculation(function, fields, value)
         assert_calculation('SUM', [@field1, @field2], "30.54")
       end
 
+      it "works with the special values Infinity and NaN" do
+        @field1.field_value = "Infinity"
+        assert_calculation('SUM', [@field1, @field2], "Infinity")
+        @field1.field_value = "NaN"
+        assert_calculation('SUM', [@field1, @field2], "NaN")
+      end
+
       it "returns nil if a field cannot be resolved" do
         @action[:JS] = 'AFSimple_Calculate("SUM", ["unknown"]);'
         assert_nil(@klass.calculate(@form, @action))