FIX: PARSE's INSERT used after a seek puts data at the position before the seek

resolves: Oldes/Rebol-issues#2269

Author: Oldes

src/core/u-parse.c

@@ -832,6 +832,12 @@ void Print_Parse_Index(REBCNT type, REBVAL *rules, REBSER *series, REBCNT index)
 					if (!ANY_SERIES(item)) Trap1(RE_PARSE_SERIES, rules-1);
 					index = Set_Parse_Series(parse, item);
 					series = parse->series;
+
+					// #2269 - reset the position if we are not in the middle of any rule
+					// don't allow code like: [copy x :pos integer!]
+					if (flags != 0) Trap1(RE_PARSE_RULE, rules-1); 
+                    begin = index;
+
 					continue;
 				}
 

src/tests/units/parse-test.r3

@@ -220,6 +220,42 @@ Rebol [
 		val = "f"
 		pos = ser
 	]
+--test-- "get-word use"
+;@@ https://github.com/Oldes/Rebol-issues/issues/2269
+	s: copy "ab"
+	--assert all [
+		parse s [p: to end :p insert "x" to end]
+		s = "xab"
+		p = s
+	]
+	s: copy "ab"
+	--assert all [
+		parse s [p: 1 skip :p insert "x" to end]
+		s = "xab"
+		p = s
+	]
+	s: copy "ab"
+	--assert all [
+		parse s [1 skip p: 1 skip :p insert "x" to end]
+		s = "axb"
+		p = "xb"
+	]
+	s: copy "abcd"
+	--assert all [
+		error? e: try [parse s [x: "ab" thru :s "abcd"]]
+		e/id = 'parse-rule
+	]
+	--assert parse s [x: "ab" :s thru "abcd"]
+	s: copy "abcd" parse s ["ab" p: "c" :p copy x to end]
+	--assert all [p = "cd" x = "cd"]
+	s: copy "abcd" parse s ["ab" p: "c" :p set x to end]
+	--assert all [p = "cd" x = #"c"] 
+	--assert all [
+		; get-word used in middle of the rule
+		error? e: try [parse "abcd" [x: "ab" copy y :s thru "abcd"]]
+		e/id = 'parse-rule
+		e/arg1 = quote :s
+	]
 
 ===end-group===