[display] fix ESwitch subject preprocessing

closes #7972

src/context/display/display.ml

@@ -150,7 +150,7 @@ module ExprPreprocessing = struct
 		in
 		let rec map e = match fst e with
 			| ESwitch(e1,cases,def) when is_annotated (pos e) ->
-				let e1 = loop e1 in
+				let e1 = map e1 in
 				let cases = List.map (fun (el,eg,e,p) ->
 					let old = !in_pattern in
 					in_pattern := true;

tests/display/src/cases/Issue7972.hx

@@ -0,0 +1,20 @@
+package cases;
+
+class Issue7972 extends DisplayTestCase {
+	/**
+		class Main {
+			static function main() {
+				var foo = 0.0;
+
+				switch (S{-1-}td.i{-2-}nt(fo{-3-}o)) {
+					case _:
+				}
+			}
+		}
+	**/
+	function test() {
+		eq("Class<Std>", type(pos(1)));
+		eq("(x : Float) -> Int", type(pos(2)));
+		eq("Float", type(pos(3)));
+	}
+}