FIX: DELINE / ENLINE does not check series' protection

fixes: metaeducation/rebol-issues#2325

Author: Oldes

src/core/n-strings.c

@@ -573,6 +573,8 @@ static struct digest {
 	REBINT len = VAL_LEN(val);
 	REBINT n;
 
+	if (IS_PROTECT_SERIES(VAL_SERIES(val))) Trap0(RE_PROTECTED);
+
 	if (D_REF(2)) { //lines
 		Set_Block(D_RET, Split_Lines(val));
 		return R_RET;
@@ -603,6 +605,8 @@ static struct digest {
 	REBVAL *val = D_ARG(1);
 	REBSER *ser = VAL_SERIES(val);
 
+	if (IS_PROTECT_SERIES(VAL_SERIES(val))) Trap0(RE_PROTECTED);
+
 	if (SERIES_TAIL(ser)) {
 		if (VAL_BYTE_SIZE(val))
 			Enline_Bytes(ser, VAL_INDEX(val), VAL_LEN(val));

src/tests/units/protect-test.r3

@@ -39,6 +39,12 @@ Rebol [
 	--test-- "swap string" --assert is-protected-error? [swap str "0bad"]
 	--test-- "swap binary" --assert is-protected-error? [swap bin #{0bad}]
 
+	;@@ https://github.com/rebol/rebol-issues/issues/2325
+	str: protect "a^M^/b"
+	--test-- "deline string"  --assert is-protected-error? [deline str]
+	--test-- "enline string"  --assert is-protected-error? [enline str]
+
+
 ===end-group===
 
 ~~~end-file~~~