FIX: correctly handling case where result from script evaluation is unset

Oldes · Oldes · commit 615e82ba42ae · 2019-04-29T13:04:43.000+02:00
related to: metaeducation/rebol-issues#2374
diff --git a/src/mezz/sys-base.r b/src/mezz/sys-base.r
@@ -98,7 +98,7 @@ do*: func [
 		]
 		; Restore system/script and the dir
 		all [system/script: :scr  dir  change-dir dir]
-		value
+		:value
 	]
 ]
 
diff --git a/src/tests/units/evaluation-test.r3 b/src/tests/units/evaluation-test.r3
@@ -60,6 +60,10 @@ Rebol [
 		dir: what-dir
 		--assert error? do %units/files/error.r3
 		--assert dir = what-dir
+
+	--test-- "script returning UNSET value"
+		--assert unset? do %units/files/unset.r3
+
 ===end-group===
 
 ===start-group=== "do function"
diff --git a/src/tests/units/files/unset.r3 b/src/tests/units/files/unset.r3
@@ -0,0 +1,2 @@
+Rebol [title: "Script which returns UNSET"] 
+print "Hello"

Original file line number	Diff line number	Diff line change
`@@ -98,7 +98,7 @@ do*: func [`
`98`	`98`	`]`
`99`	`99`	`; Restore system/script and the dir`
`100`	`100`	`all [system/script: :scr dir change-dir dir]`
`101`		`- value`
	`101`	`+ :value`
`102`	`102`	`]`
`103`	`103`	`]`
`104`	`104`
Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,2 @@`
	`1`	`+Rebol [title: "Script which returns UNSET"]`
	`2`	`+print "Hello"`