Axlsx.sanitize() writes in place or copies on write

Depending on whether a string is frozen, either a new string is created sanitized or the existing string is modified in place.

1 files changed, 6 insertions, 2 deletions

diff --git a/lib/axlsx.rb b/lib/axlsx.rb
index 20b5cab0..586562f6 100644
--- a/lib/axlsx.rb
+++ b/lib/axlsx.rb
@@ -136,8 +136,12 @@ module Axlsx
   # @param [String] str The string to process
   # @return [String]
   def self.sanitize(str)
-    str.delete(CONTROL_CHARS)
-    str
+    if str.frozen?
+      str.delete(CONTROL_CHARS)
+    else
+      str.delete!(CONTROL_CHARS)
+      str
+    end
   end
 
   # If value is boolean return 1 or 0