From 6aa6f52850fc4a2e361a654a14a91199c6c34660 Mon Sep 17 00:00:00 2001
From: Jeremy Evans <code@jeremyevans.net>
Date: Tue, 8 Oct 2024 16:21:36 -0700
Subject: [PATCH] Avoid spurious frozen string literal warnings on Ruby
 3.4.0-preview2

---
 CHANGELOG    |  4 ++++
 lib/erubi.rb | 19 ++++++++++++++-----
 2 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/CHANGELOG b/CHANGELOG
index 81be9ff..9d8e8be 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,7 @@
+=== master
+
+* Avoid spurious frozen string literal warnings on Ruby 3.4.0-preview2 (jeremyevans)
+
 === 1.13.0 (2024-06-13)
 
 * Define Erubi.h as a module function (jeremyevans)
diff --git a/lib/erubi.rb b/lib/erubi.rb
index dd7db06..35ea4fd 100644
--- a/lib/erubi.rb
+++ b/lib/erubi.rb
@@ -205,16 +205,25 @@ def initialize(input, properties={})
 
     private
 
+    if RUBY_VERSION >= '2.3'
+      def _dup_string_if_frozen(string)
+        +string
+      end
+    # :nocov:
+    else
+      def _dup_string_if_frozen(string)
+        string.frozen? ? string.dup : string
+      end
+    end
+    # :nocov:
+
     # Add raw text to the template.  Modifies argument if argument is mutable as a memory optimization.
     # Must be called with a string, cannot be called with nil (Rails's subclass depends on it).
     def add_text(text)
       return if text.empty?
 
-      if text.frozen?
-        text = text.gsub(/['\\]/, '\\\\\&')
-      else
-        text.gsub!(/['\\]/, '\\\\\&')
-      end
+      text = _dup_string_if_frozen(text)
+      text.gsub!(/['\\]/, '\\\\\&')
 
       with_buffer{@src << " << '" << text << @text_end}
     end