FEAT: store user's persistent data before releasing existing user

Author: Oldes

src/mezz/mezz-shell.reb

@@ -70,7 +70,12 @@ su: set-user: func[
 	/local su
 ][
 	su: system/user
-	if unset? :name [su/name: none su/data: make map! 1 exit]
+	if unset? :name [
+		try [update su/data] ;; save changes if there are any
+		su/name: none
+		su/data: make map! 1
+		exit
+	]
 
 	sys/log/info 'REBOL ["Initialize user:" as-green :name]
 

src/tests/units/codecs-test.r3

@@ -780,6 +780,13 @@ if find codecs 'safe [
 			--assert not error? try [set-user/n/p temp-user "passw"]
 			--assert system/user/name = @temp-user
 			--assert 'file = exists? try [system/user/data/spec/ref]
+			--assert put system/user/data 'key "hello"  ;; store some data...
+			--assert "hello" = user's key               ;; resolve the data
+			--assert not error? try [su]                ;; release user
+			--assert none? system/user/name
+			--assert not error? try [set-user/p temp-user "passw"]
+			--assert "hello" = user's key               ;; resolve the data
+
 			try [delete system/user/data/spec/ref]
 
 	===end-group===