FIX: letting FORALL to reset position, when make it through normally,…

… but not on BREAK/THROW/ERROR

So it is compatible with current Rebol2 and Red.

Not like [my previous attempt](0612b72) Where I was considering the [older Rebol2 behavior](http://www.rebol.com/docs/words/wforall.html), which is no longer valid in Rebol 2.7.8 and Red.

Related issue: metaeducation/rebol-issues#2331

src/core/n-loop.c

@@ -255,7 +255,7 @@
 			if (THROWN(ds)) {	// Break, throw, continue, error.
 				if (Check_Error(ds) >= 0) {
 					*DS_RETURN = *DS_NEXT;
-					break;
+					return R_RET; // does not resets series position
 				}
 			}
 			*DS_RETURN = *ds;
@@ -267,7 +267,9 @@
 	}
 	else Trap_Arg(var);
 
-	*D_RET = *var;
+	// !!!!! ???? allowed to write VAR????
+	*var = *DS_ARG(1);
+	//*D_RET = *var;
 	return R_RET;
 }
 

src/mezz/base-funcs.r

@@ -101,7 +101,6 @@ cause-error: func [
 			change/only args spec-of first args
 		]
 	]
-	args: head args 
 	; Build and throw the error:
 	do make error! [
 		type: err-type

src/tests/units/series-test.r3

@@ -116,7 +116,12 @@ Rebol [
 	;-- compatible with R2 & Red - the series is at its tail
 	data: [1 2 3 4]
 	--assert unset? forall data []
-	--assert tail? data
+	--assert data = [1 2 3 4]
+	data: next data
+	--assert unset? forall data []
+	--assert data = [2 3 4]
+	--assert 4 = forall data [data/1]
+	--assert data = [2 3 4]
 
 ;@@ https://github.com/rebol/rebol-issues/issues/2331
 --test-- "Escaping from FORALL loop using THROW"