Fix offenses in sheet protection

- Lint/AmbiguousOperatorPrecedence
- Style/PerlBackrefs
- Style/StringChars
- Style/UnpackFirst

1 files changed, 5 insertions, 5 deletions

diff --git a/lib/axlsx/workbook/worksheet/sheet_protection.rb b/lib/axlsx/workbook/worksheet/sheet_protection.rb
index ce39b1b4..abf5e452 100644
--- a/lib/axlsx/workbook/worksheet/sheet_protection.rb
+++ b/lib/axlsx/workbook/worksheet/sheet_protection.rb
@@ -87,25 +87,25 @@ module Axlsx
       encoded_password = encode_password(password)
 
       password_as_hex = [encoded_password].pack("v")
-      password_as_string = password_as_hex.unpack("H*").first.upcase
+      password_as_string = password_as_hex.unpack1("H*").upcase
 
       password_as_string[2..3] + password_as_string[0..1]
     end
 
     # Encodes a given password
     # Based on the algorithm provided by Daniel Rentz of OpenOffice.
-    # http://www.openoffice.org/sc/excelfileformat.pdf, Revision 1.42, page 115 (21.05.2012)
+    # https://www.openoffice.org/sc/excelfileformat.pdf, Revision 1.42, page 115 (21.05.2012)
     # @return [String]
     def encode_password(password)
       i = 0
-      chars = password.split("")
+      chars = password.chars
       count = chars.size
 
       chars.collect! do |char|
         i += 1
-        char     = char.unpack('c')[0] << i # ord << i
+        char     = char.unpack1('c') << i # ord << i
         low_15   = char & 0x7fff
-        high_15  = char & 0x7fff << 15
+        high_15  = char & (0x7fff << 15)
         high_15  = high_15 >> 15
         low_15 | high_15
       end