From: ruby@... Date: 2017-09-28T20:26:12+00:00 Subject: [ruby-core:83055] [Ruby trunk Bug#13949] String#unpack with 'M' directive can create strings with wrong code range Issue #13949 has been reported by nirvdrum (Kevin Menard). ---------------------------------------- Bug #13949: String#unpack with 'M' directive can create strings with wrong code range https://bugs.ruby-lang.org/issues/13949 * Author: nirvdrum (Kevin Menard) * Status: Open * Priority: Normal * Assignee: * Target version: * ruby -v: * Backport: 2.3: UNKNOWN, 2.4: UNKNOWN ---------------------------------------- I've noticed that String#unpack with the 'M' directive can create strings that should be CR_7BIT as CR_VALID. The issue appears to have been introduced in r30542, which assumes that all ASCII-8BIT strings must be CR_VALID. It's possible this was correct back during Ruby 1.9.3 development and just wasn't updated. I'm not familiar enough with the history to tell. A simple reproduction showing the issue is: ``` res = '0123456789=\n'.unpack('M').first p res p res.encoding p res.bytes p res.ascii_only? puts packed = res.bytes.pack('c*') p packed p packed.encoding p packed.bytes p packed.ascii_only? ``` This yields the following output: ``` "0123456789=\\n" # [48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 61, 92, 110] false "0123456789=\\n" # [48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 61, 92, 110] true ``` Both strings have exactly the same contents with the same encoding. But, depending on how you construct them, one is consider to be CR_7BIT (indicated by the String#ascii_only?) value, and one is considered to be CR_VALID. I believe CR_7BIT is the correct code range value in this situation. -- https://bugs.ruby-lang.org/ Unsubscribe: