From: merch-redmine@... Date: 2019-06-19T02:07:27+00:00 Subject: [ruby-core:93238] [Ruby trunk Bug#15926] Edge case issue with String#uminus Issue #15926 has been updated by jeremyevans0 (Jeremy Evans). File str-uminus-freeze-fix.patch added I agree that this is a bug. I'm not sure if `rb_fstring`'s behavior should be changed (hopefully a more knowledgeable committer can weigh in), so a conservative approach to fix this is to dup the receiver before passing to `rb_fstring`, if the receiver's class is not `String` and the object is not already frozen. The attached patch does this. ---------------------------------------- Bug #15926: Edge case issue with String#uminus https://bugs.ruby-lang.org/issues/15926#change-78688 * Author: luke-gru (Luke Gruber) * Status: Open * Priority: Normal * Assignee: * Target version: * ruby -v: * Backport: 2.4: UNKNOWN, 2.5: UNKNOWN, 2.6: UNKNOWN ---------------------------------------- I was working on issue related to code in `rb_fstring`(https://github.com/ruby/ruby/pull/2233) and saw some weird behavior in the function, freezing the given string if it's not a "bare" string and it's small enough to be embedded. The issue comes up in the following edge case: class MyString < String end non_frozen = MyString.new("nonfrozen") frozen = -non_frozen # deduplicates, but shouldn't freeze receiver non_frozen << " added" # raises FrozenError I'm not sure what the correct behavior should be with a subclass and String#uminus. Should it return a frozen regular String or a frozen copy of the given class's string? Not a practical concern (not often come upon I'm sure), but I think a valid one. ---Files-------------------------------- str-uminus-freeze-fix.patch (1.38 KB) -- https://bugs.ruby-lang.org/ Unsubscribe: