diff -Nru cygwin/bin/mkzsh cygwin/bin/mkzsh
--- cygwin/bin/mkzsh	1970-01-01 09:00:00.000000000 +0900
+++ cygwin/bin/mkzsh	2020-06-04 05:26:04.926454800 +0900
@@ -0,0 +1,73 @@
+#!/bin/zsh
+
+ME=`basename $0`
+batfile=/zsh.bat
+iconpath=/cygwin.ico
+shortcutname="Cygwin Zsh"
+
+all_opt=""
+do_desktop=""
+do_menu=""
+
+#rootpath=`regtool get '/machine/SOFTWARE/Cygnus Solutions/Cygwin/mounts v2/\//native'`
+rootpath=`mount | grep ' / ' | awk '{ print $1 }' | tr / '\\\\'`
+rootdrive=`echo "$rootpath" | sed 's/\(.:\).*/\1/'`
+
+CreateZshBat()
+{
+  echo "Creating $batfile ..."
+# Create the zsh.bat file
+
+ cat > $batfile <<EOF
+@echo off
+$rootdrive
+chdir $rootpath\bin
+zsh -l -i
+EOF
+
+ chmod a+rx $batfile
+}
+
+CreateDesktop()
+{
+ echo "Creating Desktop Icon..."
+ mkshortcut -D $all_opt --icon $iconpath --name "$shortcutname" --arguments="$rootpath" $batfile
+}
+
+CreateMenu()
+{
+ echo "Creating Menu Item..."
+ mkshortcut -P $all_opt --icon $iconpath --name "$shortcutname" --arguments="$rootpath" $batfile
+}
+
+Usage()
+{
+  cat << EOF
+Usage: $ME {-A} {-D} {-P} {-h|--help}
+  -A|--allusers      creates item for All Users instead of just current user
+  -D|--desktop       creates a Desktop icon for running $batfile
+  -P|--smprograms    creates a Program menu item for running $batfile
+  -h|--help          prints usage
+EOF
+  exit 2
+}
+
+# main
+
+while [ $# != 0 ]
+do
+ case "$1" in
+-A|--allusers)   all_opt="--allusers" ;;
+-D|--desktop)    do_desktop="1" ;;
+-P|--smprograms) do_menu="1" ;;
+-h|--help)       Usage ;;
+ esac
+ shift 
+done
+
+CreateZshBat
+
+[ "$do_desktop" != "" ] && CreateDesktop
+[ "$do_menu" != "" ] && CreateMenu
+
+exit 0
diff -Nru cygwin/profile.d/zshell.zsh cygwin/profile.d/zshell.zsh
--- cygwin/profile.d/zshell.zsh	1970-01-01 09:00:00.000000000 +0900
+++ cygwin/profile.d/zshell.zsh	2020-06-04 05:26:04.929475400 +0900
@@ -0,0 +1,4 @@
+# set SHELL if not set
+if [ ! -z "$ZSH_NAME" -a -z "$SHELL" ]; then
+  export SHELL="/bin/zsh"
+fi
diff -Nru cygwin/startup-files/zprofile cygwin/startup-files/zprofile
--- cygwin/startup-files/zprofile	1970-01-01 09:00:00.000000000 +0900
+++ cygwin/startup-files/zprofile	2020-06-04 05:26:04.932439500 +0900
@@ -0,0 +1,224 @@
+# derived from base-files version 4.2-3
+
+# WARNING
+#
+# IF THIS FILE IS MODIFIED IT WILL NOT BE UPDATED BY THE CYGWIN
+# SETUP PROGRAM.  IT BECOMES YOUR RESPONSIBILITY.
+
+# The latest version as installed by the Cygwin Setup program can
+# always be found at /usr/share/doc/zsh-X.Y.Z/StartupFiles/etc/zprofile
+
+# Some resources...
+
+# Customizing Your Shell: http://www.dsl.org/cookbook/cookbook_5.html#SEC69
+# Consistent BackSpace and Delete Configuration:
+#   http://www.ibb.net/~anne/keyboard.html
+# The Linux Documentation Project: http://www.tldp.org/
+# The Linux Cookbook: http://www.tldp.org/LDP/linuxcookbook/html/
+# Greg's Wiki http://mywiki.wooledge.org/
+
+# Setup some default paths. Note that this order will allow user installed
+# software to override 'system' software.
+# Modifying these default path settings can be done in different ways.
+# To learn more about startup files, refer to your shell's man page.
+
+# If you wish to change the path for all users, it is recommended you edit
+#    /etc/zshenv # runs before /etc/zprofile
+# or /etc/zshrc  # runs after /etc/zprofile (for interactive shells)
+# or /etc/zlogin # runs after /etc/zprofile (for login shells)
+
+# If you wish to change the path on a user by user basis, it is recommended you
+#  edit
+#    ~/.zshenv   # runs before ~/.zprofile
+# or ~/.zprofile # (for login shells)
+# or ~/.zshrc    # runs after ~/.zprofile (for interactive shells)
+# or ~/.zlogin   # runs after ~/.zprofile (for login shells)
+
+if [ -z "${PROFILEREAD+true}" ] ; then
+
+  # Setup some default paths. Note that this order will allow user installed
+  # software to override 'system' software.
+  # Modifying these default path settings can be done in different ways.
+  # To learn more about startup files, refer to your shell's man page.
+
+  : ${ORIGINAL_PATH=${PATH}}
+  if [ ${CYGWIN_NOWINPATH-addwinpath} = "addwinpath" ] ; then
+    PATH="/usr/local/bin:/usr/bin${PATH:+:${PATH}}"
+  else
+    PATH="/usr/local/bin:/usr/bin"
+  fi
+
+# see https://cygwin.com/ml/cygwin/2014-05/msg00352.html
+# MANPATH="/usr/local/man:/usr/share/man:/usr/man${MANPATH:+:${MANPATH}}"
+  INFOPATH="/usr/local/info:/usr/share/info:/usr/info${INFOPATH:+:${INFOPATH}}"
+
+  # Set the user id
+  USER="$(/usr/bin/id -un)"
+
+  # TMP and TEMP as defined in the Windows environment
+  # can have unexpected consequences for cygwin apps, so we define
+  # our own to match GNU/Linux behaviour.
+  unset TMP TEMP
+  TMP="/tmp"
+  TEMP="/tmp"
+
+  # Define default printer
+  p='/proc/registry/HKEY_CURRENT_USER/Software/Microsoft/Windows NT/CurrentVersion/Windows/Device'
+  if [ -e "${p}" ] ; then
+    read -r PRINTER < "${p}"
+    PRINTER=${PRINTER%%,*}
+  fi
+  unset p
+
+  # Default to removing the write permission for group and other
+  #  (files normally created with mode 777 become 755; files created with
+  #  mode 666 become 644)
+  umask 022
+
+  # Here is how HOME is set, in order of priority, when starting from Windows
+  #  1) From existing HOME in the Windows environment, translated to a Posix path
+  #  2) from /etc/passwd, if there is an entry with a non empty directory field
+  #  3) from HOMEDRIVE/HOMEPATH
+  #  4) / (root)
+  # If the home directory doesn't exist, create it.
+  if [ ! -d "${HOME}" ]; then
+    if mkdir -p "${HOME}"; then
+      echo "Copying skeleton files."
+      echo "These files are for the users to personalise their cygwin experience."
+      echo
+      echo "They will never be overwritten nor automatically updated."
+      echo
+      if ! cd /etc/skel; then
+        echo "WARNING: Failed attempt to cd into /etc/skel!"
+      else
+        /usr/bin/find . -type f |
+	  while read f; do
+            fDest=${f#.}
+            if [ ! -e "${HOME}${fDest}" -a ! -L "${HOME}${fDest}" ]; then
+              /usr/bin/install -D -p -v "${f}" "${HOME}/${fDest}"
+            fi
+          done
+        unset fDest
+      fi
+    else
+      echo "${HOME} could not be created."
+      { [ -d "${TEMP}" ] && HOME="${TEMP}"; } ||
+      { [ -d "${TMP}" ] && HOME="${TMP}"; } ||
+      { [ -d /tmp ] && HOME=/tmp; } ||
+      HOME=/
+      echo "Setting HOME to ${HOME}."
+    fi
+  fi
+
+  readonly PROFILEREAD=true
+fi
+
+# Make sure we start in home unless invoked by CHERE
+if [ ! -z "${CHERE_INVOKING}" ]; then
+  unset CHERE_INVOKING
+else
+  cd "${HOME}" || echo "WARNING: Failed attempt to cd into ${HOME}!"
+fi
+
+# Shell dependent settings
+profile_d ()
+{
+  _LC_ALL_SET_="${LC_ALL+set}"
+  _LC_SAVE_="${LC_ALL-null}"
+  LC_ALL=C
+  if [ "${_LC_SAVE_}" = "null" ]; then
+    for file in /etc/profile.d/*.$1; do
+      [ -e "${file}" ] && . "${file}"
+    done
+    unset LC_ALL
+  else
+    for file in /etc/profile.d/*.$1; do
+      [ -e "${file}" ] && LC_ALL="${_LC_SAVE_}" . "${file}"
+    done
+    LC_ALL="${_LC_SAVE_}"
+  fi
+  unset file
+  unset _LC_ALL_SET_
+  unset _LC_SAVE_
+}
+
+HOSTNAME="$(/usr/bin/hostname)"
+profile_d sh
+if [ ! "x${BASH_VERSION}" = "x"  ]; then
+  [ -f "/etc/bash.bashrc" ] && . "/etc/bash.bashrc"
+elif [ ! "x${KSH_VERSION}" = "x" ]; then
+  typeset -l HOSTNAME="$(/usr/bin/hostname)"
+  [ "${PS1-null}" = "null" ] || PS1=$(print '\033]0;${PWD}\n\033[32m${USER}@${HOSTNAME} \033[33m${PWD/${HOME}/~}\033[0m\n$ ')
+elif [ ! "x${ZSH_VERSION}" = "x" ]; then
+  # zsh is in shell compatibility mode here, so we probably shouldn't do this
+  profile_d zsh
+elif [ ! "x${POSH_VERSION}" = "x" ]; then
+  : # [ "${PS1-null}" = "null" ] || PS1="$ "
+else
+  : # [ "${PS1-null}" = "null" ] || PS1="$ "
+fi
+
+# export PROFILEREAD PATH ORIGINAL_PATH MANPATH INFOPATH USER TMP TEMP PRINTER HOSTNAME PS1 SHELL tmp temp
+export PROFILEREAD PATH ORIGINAL_PATH INFOPATH USER TMP TEMP PRINTER HOSTNAME PS1 SHELL tmp temp
+
+# Check to see if mkpasswd/mkgroup needs to be run try and cut down the emails
+#   about this on the lists!
+#
+# The following are the conditions under which the group name special cases
+#   will appear (where uid and gid are the effective user and group ids
+#   for the current user, and pgsid is the primary group associated with the
+#   SID for the current user):
+#       mkpasswd:
+#         gid is not in /etc/group
+#         uid is not in /etc/passwd
+#       passwd/group_GID_clash(<gid>/<pgsid>):
+#         gid is not in /etc/group
+#         uid is in /etc/passwd
+#         pgsid is in /etc/group (and does not match gid)
+#       mkgroup:
+#         gid is not in /etc/group
+#         uid is in /etc/passwd
+#         pgsid is not in /etc/group
+#
+# If this message keeps appearing and you are sure it's a mistake (ie, don't
+#   email about it!), comment out the test below.
+case "$(/usr/bin/id -ng)" in
+mkpasswd )
+  echo "Your group is currently \"mkpasswd\".  This indicates that your"
+  echo "gid is not in /etc/group and your uid is not in /etc/passwd."
+  echo
+  echo "The /etc/passwd (and possibly /etc/group) files should be rebuilt."
+  echo "See the man pages for mkpasswd and mkgroup then, for example, run"
+  echo
+  echo "mkpasswd -l [-d] > /etc/passwd"
+  echo "mkgroup  -l [-d] > /etc/group"
+  echo
+  echo "Note that the -d switch is necessary for domain users."
+  ;;
+passwd/group_GID_clash* )
+  echo "Your group is currently \"passwd/group_GID_clash(gid/pgsid)\".  This"
+  echo "indicates that your gid is not in /etc/group, but the pgsid (primary "
+  echo "group associated with your SID) is in /etc/group."
+  echo
+  echo "The /etc/passwd (and possibly /etc/group) files should be rebuilt."
+  echo "See the man pages for mkpasswd and mkgroup then, for example, run"
+  echo
+  echo "mkpasswd -l [-d] > /etc/passwd"
+  echo "mkgroup  -l [-d] > /etc/group"
+  echo
+  echo "Note that the -d switch is necessary for domain users."
+  ;;
+mkgroup )
+  echo "Your group is currently \"mkgroup\".  This indicates that neither"
+  echo "your gid nor your pgsid (primary group associated with your SID)"
+  echo "is in /etc/group."
+  echo
+  echo "The /etc/group (and possibly /etc/passwd) files should be rebuilt."
+  echo "See the man pages for mkpasswd and mkgroup then, for example, run"
+  echo
+  echo "mkpasswd -l [-d] > /etc/passwd"
+  echo "mkgroup  -l [-d] > /etc/group"
+  echo
+  echo "Note that the -d switch is necessary for domain users."
+  ;;
+esac