`number_to_percentage` and `precision: 0` work with `NAN` and `INFINITY`.

Closes #19227.

3 files changed, 12 insertions, 1 deletions

diff --git a/activesupport/CHANGELOG.md b/activesupport/CHANGELOG.md
index f5fa70494a..1d21a18c16 100644
--- a/activesupport/CHANGELOG.md
+++ b/activesupport/CHANGELOG.md
@@ -1,3 +1,10 @@
+*   `number_to_percentage` does not crash with `Float::NAN` or `Float::INFINITY`
+    as input when `precision: 0` is used.
+
+    Fixes #19227.
+
+    *Yves Senn*
+
 *   Take DST into account when locating TimeZone from Numeric.
 
     When given a specific offset, use the first result found where the
diff --git a/activesupport/lib/active_support/number_helper/number_to_rounded_converter.rb b/activesupport/lib/active_support/number_helper/number_to_rounded_converter.rb
index df316a08e6..981c562551 100644
--- a/activesupport/lib/active_support/number_helper/number_to_rounded_converter.rb
+++ b/activesupport/lib/active_support/number_helper/number_to_rounded_converter.rb
@@ -23,7 +23,7 @@ module ActiveSupport
             precision = 0 if precision < 0 # don't let it be negative
           else
             rounded_number = number.round(precision)
-            rounded_number = rounded_number.to_i if precision == 0
+            rounded_number = rounded_number.to_i if precision == 0 && rounded_number.finite?
             rounded_number = rounded_number.abs if rounded_number.zero? # prevent showing negative zeros
           end
 
diff --git a/activesupport/test/number_helper_test.rb b/activesupport/test/number_helper_test.rb
index 23996ef381..83efbffdfb 100644
--- a/activesupport/test/number_helper_test.rb
+++ b/activesupport/test/number_helper_test.rb
@@ -83,6 +83,10 @@ module ActiveSupport
           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))
+          assert_equal("NaN%", number_helper.number_to_percentage(Float::NAN, precision: 0))
+          assert_equal("Inf%", number_helper.number_to_percentage(Float::INFINITY, precision: 0))
+          assert_equal("NaN%", number_helper.number_to_percentage(Float::NAN, precision: 1))
+          assert_equal("Inf%", number_helper.number_to_percentage(Float::INFINITY, precision: 1))
           assert_equal("1000%", number_helper.number_to_percentage(1000, precision: nil))
           assert_equal("1000%", number_helper.number_to_percentage(1000, precision: nil))
           assert_equal("1000.1%", number_helper.number_to_percentage(1000.1, precision: nil))