[nullsafety] fix chained && and || (closes #7820)

.gitignore

@@ -65,6 +65,7 @@
 /tests/unit/node_modules/
 
 /tests/nullsafety/bin
+/tests/nullsafety/dump
 
 /haxe.sublime*
 .idea

src/typing/nullSafety.ml

@@ -324,7 +324,7 @@ let rec can_pass_type src dst =
 	Collect nullable local vars which are checked against `null`.
 	Returns a tuple of (vars_checked_to_be_null * vars_checked_to_be_not_null) in case `condition` evaluates to `true`.
 *)
-let process_condition loose_safety condition (is_nullable_expr:texpr->bool) callback =
+let rec process_condition loose_safety condition (is_nullable_expr:texpr->bool) callback =
 	let nulls = ref []
 	and not_nulls = ref [] in
 	let add to_nulls expr =
@@ -347,11 +347,25 @@ let process_condition loose_safety condition (is_nullable_expr:texpr->bool) call
 			| TBinop (OpEq, checked_expr, e) when is_suitable loose_safety checked_expr && not (is_nullable_expr e) ->
 				if positive then not_nulls := checked_expr :: !not_nulls
 			| TBinop (OpBoolAnd, left_expr, right_expr) when positive ->
-				traverse positive left_expr;
-				traverse positive right_expr
+					traverse positive left_expr;
+					traverse positive right_expr
+			| TBinop (OpBoolAnd, left_expr, right_expr) when not positive ->
+					List.iter
+						(fun e ->
+							let _, not_nulls = process_condition loose_safety left_expr is_nullable_expr callback in
+							List.iter (add true) not_nulls
+						)
+						[left_expr; right_expr]
 			| TBinop (OpBoolOr, left_expr, right_expr) when not positive ->
-				traverse positive left_expr;
-				traverse positive right_expr
+					traverse positive left_expr;
+					traverse positive right_expr
+			| TBinop (OpBoolOr, left_expr, right_expr) when positive ->
+				List.iter
+					(fun e ->
+						let nulls, _ = process_condition loose_safety left_expr is_nullable_expr callback in
+						List.iter (add true) nulls
+					)
+					[left_expr; right_expr]
 			| TParenthesis e -> traverse positive e
 			| _ -> callback e
 	in
@@ -831,7 +845,8 @@ class local_safety (mode:safety_mode) =
 			Handle boolean AND outside of `if` condition.
 		*)
 		method process_and left_expr right_expr is_nullable_expr (callback:texpr->unit) =
-			let (_, not_nulls) = process_condition (mode <> SMStrict) left_expr is_nullable_expr callback in
+			callback left_expr;
+			let (_, not_nulls) = process_condition (mode <> SMStrict) left_expr is_nullable_expr (fun e -> ()) in
 			List.iter self#get_current_scope#add_to_safety not_nulls;
 			callback right_expr;
 			List.iter self#get_current_scope#remove_from_safety not_nulls

tests/nullsafety/src/cases/TestLoose.hx

@@ -64,4 +64,15 @@ class TestLoose {
 		}
 		bar();
 	}
+
+	static var struct:Null<{foo:String}>;
+
+	static function checkAgainstNull_checkAndFieldAccess() {
+		struct == null
+			|| struct.foo != ""
+			|| struct.foo != "";
+		struct != null
+			&& struct.foo != ""
+			&& struct.foo != "";
+	}
 }

tests/nullsafety/src/cases/TestStrict.hx

@@ -345,27 +345,35 @@ class TestStrict {
 		}
 	}
 
-	static function checkAgainstNull_checkAndFieldAccess(?a:String) {
-		var s:Null<String> = null;
+	static function checkAgainstNull_checkAndFieldAccess(?a:String, ?s:String) {
 		if(s != null && s.length == 0) {}
 		if(s == null || s.length == 0) {}
-		s != null && s.length == 0;
-		s == null || s.length == 0;
+		s != null
+			&& s.length == 0
+			&& s.length == 0;
+		s == null
+			|| s.length == 0
+			|| s.length == 0;
 		!(s == null || a == null) && s.length == a.length;
 
 		shouldFail(if(s != null || s.length == 0) {});
 		shouldFail(if(s == null && s.length == 0) {});
 		shouldFail(s != null || s.length == 0);
 		shouldFail(s == null && s.length == 0);
+	}
 
-		//checked against not-nullable value, so it's not null
-		var nullable:Null<String> = null;
+	static function checkedAgainstNotNullableValue(?a:String) {
 		var s = 'world';
-		if(nullable == s) {
-			s = nullable;
+		if(a == s) {
+			a.charAt(0);
 		} else {
-			shouldFail(s = nullable);
+			shouldFail(a.charAt(0));
 		}
+		// if(a != s) {
+		// 	shouldFail(a.charAt(0));
+		// } else {
+		// 	a.charAt(0);
+		// }
 	}
 
 	static function checkedAgainstNull_nullifiedAfterCheck_shouldFail(?a:String) {