FIX: Path evaluation does not process THROWN values as THROWN

resolves: Oldes/Rebol-issues#2243

Author: Oldes

src/core/c-do.c

@@ -433,6 +433,10 @@ void Trace_Arg(REBINT num, REBVAL *arg, REBVAL *path)
 		pvs->value = pvs->store;
 		break;
 	case PE_BAD_SELECT:
+		if (THROWN(pvs->select)) {
+			pvs->value = pvs->select;
+			return;
+		}
 		Trap2(RE_INVALID_PATH, pvs->orig, pvs->path);
 	case PE_BAD_SET:
 		Trap2(RE_BAD_PATH_SET, pvs->orig, pvs->path);
@@ -491,15 +495,19 @@ void Trace_Arg(REBINT num, REBVAL *arg, REBVAL *path)
 		Next_Path(&pvs);
 		// Check for errors:
 		if (NOT_END(pvs.path+1) && !ANY_FUNC(pvs.value)) {
+			if (THROWN(pvs.value)) goto thrown;
 			// Only function refinements should get by this line:
 			Trap2(RE_INVALID_PATH, pvs.orig, pvs.path);
 		}
 	}
-	else if (NOT_END(pvs.path+1) && !ANY_FUNC(pvs.value))
+	else if (NOT_END(pvs.path+1) && !ANY_FUNC(pvs.value)) {
+		if (THROWN(pvs.value)) goto thrown;
 		Trap2(RE_BAD_PATH_TYPE, pvs.orig, Of_Type(pvs.value));
+	}
 
 	// If SET then we can drop result storage created above.
 	if (val) {
+		if (THROWN(pvs.value)) goto thrown;
 		DS_DROP; // on SET, we do not care about returned value
 		return 0;
 	} else {
@@ -511,6 +519,10 @@ void Trace_Arg(REBINT num, REBVAL *arg, REBVAL *path)
 		*path_val = pvs.path; // return new path (for func refinements)
 		return pvs.value; // only used for functions
 	}
+thrown:
+	if (val) DS_DROP;
+	*DS_TOP = *pvs.value;
+	return 0;
 }
 
 

src/tests/units/evaluation-test.r3

@@ -804,6 +804,14 @@ Rebol [
 		--assert error? catch [make error! [type: 'Access arg1: 10 + 20 id: 'Protocol]]
 		--assert 30 = catch [make error! [type: 'Access arg1: throw 10 + 20 id: 'Protocol]]
 
+	--test-- "throw from path evaluation"
+	;@@ https://github.com/Oldes/Rebol-issues/issues/2243
+		foo: object [bar: 1]
+		--assert "ok" = catch [foo/(throw "ok" 'bar)]
+		--assert "ok" = catch [foo/(throw "ok" 'bar): 3]
+		--assert "ok" = catch [foo/(throw "ok" 'bar)/xx]
+		--assert "ok" = catch [foo/(throw "ok" 'bar)/xx: 3]
+
 ===end-group===