CHANGE: allow making error using error as a make's type

related to: Oldes/Rebol-issues#993

Author: Oldes

src/core/t-object.c

@@ -396,6 +396,11 @@ static REBSER *Trim_Object(REBSER *obj)
 				break; // returns obj
 			}
 		}
+		else if (IS_ERROR(value)) {
+			Make_Error_Object(arg, value); // arg is block/string, returns value
+			type = 0;
+			break; // returns value
+		}
 		Trap_Make(VAL_TYPE(value), value);
 
 	case A_TO:

src/tests/units/error-test.r3

@@ -24,6 +24,12 @@ Rebol [
 		e/type = 'Math
 		e/id   = 'overflow
 	]
+	;@@ https://github.com/Oldes/Rebol-issues/issues/993
+	--assert all [
+		error? e: make e "message"
+		e/type = 'User
+		e/arg1 = "message"
+	]
 
 	--test-- "make invalid error!"
 	;@@ https://github.com/Oldes/Rebol-issues/issues/1002