[ruby-core:116965] [Ruby master Bug#20307] `Hash#update` from compare_by_identity hash can have unfrozen string keys

Issue #20307 has been reported by nobu (Nobuyoshi Nakada). ---------------------------------------- Bug #20307: `Hash#update` from compare_by_identity hash can have unfrozen string keys https://bugs.ruby-lang.org/issues/20307 * Author: nobu (Nobuyoshi Nakada) * Status: Open * Backport: 3.0: REQUIRED, 3.1: REQUIRED, 3.2: REQUIRED, 3.3: REQUIRED ---------------------------------------- I don't think this behavior is expected. ```ruby i = Hash.new.compare_by_identity k = "a" i[k] = 0 h = {}.update(i) p h["a"] # => 0 k.upcase! p h.fetch(k) # in 'Hash#fetch': key not found: "A" (KeyError) ``` -- https://bugs.ruby-lang.org/