Bug #20466: Interpolated regular expressions have different encoding than interpolated strings

• Status: Open
• Assignee: -
• Target version: -
• Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN

[tenderlovemaking (Aaron Patterson)]

When the encoding is set to US-ASCII, interpolated strings can have different encoding than interpolated regular expressions. I think they should have the same encoding:

# encoding: US-ASCII

t0 = '\\xc1'
t1 = "#{t0}"
re = /#{t0}/

p [t0.encoding, t1.encoding, re.encoding]

Output is:

$ ./miniruby -v test.rb
ruby 3.4.0dev (2024-05-02T15:27:18Z master 7c0cf71049) [arm64-darwin23]
[#<Encoding:US-ASCII>, #<Encoding:US-ASCII>, #<Encoding:BINARY (ASCII-8BIT)>]

[Eregon (Benoit Daloze)]

• Related to Misc #20407: Question about applying encoding modifier to an interpolated Regexp added