From b58b97fe23a0725f2de9943ad72634aed3d5073f Mon Sep 17 00:00:00 2001
From: Robert Haines <rhaines@manchester.ac.uk>
Date: Sun, 27 Oct 2019 10:29:27 +0000
Subject: [PATCH] UniversalTime: correctly set the flags.

When a timestamp is set/unset the flags should reflect this.
---
 lib/zip/extra_field/universal_time.rb | 31 +++++++++++++++++++++------
 1 file changed, 25 insertions(+), 6 deletions(-)

diff --git a/lib/zip/extra_field/universal_time.rb b/lib/zip/extra_field/universal_time.rb
index 453b539..39c292c 100644
--- a/lib/zip/extra_field/universal_time.rb
+++ b/lib/zip/extra_field/universal_time.rb
@@ -4,24 +4,43 @@ module Zip
     HEADER_ID = 'UT'
     register_map
 
+    ATIME_MASK = 0b010
+    CTIME_MASK = 0b100
+    MTIME_MASK = 0b001
+
     def initialize(binstr = nil)
       @ctime = nil
       @mtime = nil
       @atime = nil
-      @flag  = nil
+      @flag  = 0
       binstr && merge(binstr)
     end
 
-    attr_accessor :atime, :ctime, :mtime, :flag
+    attr_reader :atime, :ctime, :mtime, :flag
+
+    def atime=(time)
+      @flag = time.nil? ? @flag & ~ATIME_MASK : @flag | ATIME_MASK
+      @atime = time
+    end
+
+    def ctime=(time)
+      @flag = time.nil? ? @flag & ~CTIME_MASK : @flag | CTIME_MASK
+      @ctime = time
+    end
+
+    def mtime=(time)
+      @flag = time.nil? ? @flag & ~MTIME_MASK : @flag | MTIME_MASK
+      @mtime = time
+    end
 
     def merge(binstr)
       return if binstr.empty?
       size, content = initial_parse(binstr)
       size || return
-      @flag, mtime, atime, ctime = content.unpack('CVVV')
-      mtime && @mtime ||= ::Zip::DOSTime.at(mtime)
-      atime && @atime ||= ::Zip::DOSTime.at(atime)
-      ctime && @ctime ||= ::Zip::DOSTime.at(ctime)
+      @flag, mt, at, ct = content.unpack('CVVV')
+      mt && @mtime ||= ::Zip::DOSTime.at(mt)
+      at && @atime ||= ::Zip::DOSTime.at(at)
+      ct && @ctime ||= ::Zip::DOSTime.at(ct)
     end
 
     def ==(other)