Encoding a string with undefined chars fails with NoMethodError #9009
Description
Environment Information
Provide at least:
- JRuby version (
jruby -v) and command line (flags, JRUBY_OPTS, etc) - 10.0.1.0 / 10.0.2.0
Other relevant info you may wish to add:
- Installed or activated gems
- Application/framework version (e.g. Rails, Sinatra)
- Environment variables
Expected Behavior
Should raise a UndefinedConversionError which it does unless invalid: argument is provided:
ruby -v -e 'p "1ĀŽ2".encode("windows-1252")'
jruby 9.4.13.0 (3.1.4) 2025-06-10 9938a3461f OpenJDK 64-Bit Server VM 21.0.2+13-58 on 21.0.2+13-58 +jit [x86_64-linux]
Encoding::UndefinedConversionError: "\xC4\x80" to WINDOWS-1252 in conversion from UTF-8 to WINDOWS-1252
encode at org/jruby/RubyString.java:6698
<main> at -e:1
jruby 10.0.2.0 (3.4.2) 2025-08-07 cba6031bd0 OpenJDK 64-Bit Server VM 21.0.2+13-58 on 21.0.2+13-58 +indy +jit [x86_64-linux]
Encoding::UndefinedConversionError: "\xC4\x80" to WINDOWS-1252 in conversion from UTF-8 to WINDOWS-1252
encode at org/jruby/RubyString.java:6840
<main> at -e:1
ruby -v -e 'p "1ĀŽ2".encode("windows-1252", invalid: :replace, replace: "")'
ruby 3.4.6 (2025-09-16 revision dbd83256b1) +PRISM [x86_64-linux]
-e:1:in 'String#encode': U+0100 to WINDOWS-1252 in conversion from UTF-8 to WINDOWS-1252 (Encoding::UndefinedConversionError)
from -e:1:in '<main>'
Actual Behavior
ruby -v -e 'p "1ĀŽ2".encode("windows-1252", invalid: :replace, replace: "")'
(JRuby 9.4 treats invalid as undef arg)
jruby 9.4.13.0 (3.1.4) 2025-06-10 9938a3461f OpenJDK 64-Bit Server VM 21.0.2+13-58 on 21.0.2+13-58 +jit [x86_64-linux]
"1\x8E2"
ruby -v -e 'p "1ĀŽ2".encode("windows-1252", invalid: :replace, replace: "")'
(JRuby 10 raises NoMethodError instead of Encoding::UndefinedConversionError)
jruby 10.0.2.0 (3.4.2) 2025-08-07 cba6031bd0 OpenJDK 64-Bit Server VM 21.0.2+13-58 on 21.0.2+13-58 +indy +jit [x86_64-linux]
NoMethodError: undefined method '[]' for nil
encode at org/jruby/RubyString.java:6845
<main> at -e:1