fix #3980

jscomp/core/js_dump.ml

@@ -171,6 +171,7 @@ let exp_need_paren  (e : J.expression) =
   | Raw_js_code (_, Exp)
   | Fun _ 
   | Raw_js_function _ 
+  | Caml_block (_,_,_, (Blk_record _ | Blk_module _))
   | Object _ -> true
   | Raw_js_code (_,Stmt)
   | Length _

jscomp/test/build.ninja

@@ -312,6 +312,7 @@ build test/gpr_3877_test.cmi test/gpr_3877_test.cmj : cc test/gpr_3877_test.ml |
 build test/gpr_3895_test.cmi test/gpr_3895_test.cmj : cc test/gpr_3895_test.ml | $stdlib
 build test/gpr_3897_test.cmi test/gpr_3897_test.cmj : cc test/gpr_3897_test.ml | $stdlib
 build test/gpr_3931_test.cmi test/gpr_3931_test.cmj : cc test/gpr_3931_test.ml | $stdlib
+build test/gpr_3980_test.cmi test/gpr_3980_test.cmj : cc test/gpr_3980_test.ml | $stdlib
 build test/gpr_405_test.cmj : cc_cmi test/gpr_405_test.ml | test/gpr_405_test.cmi $stdlib
 build test/gpr_405_test.cmi : cc test/gpr_405_test.mli | $stdlib
 build test/gpr_441.cmi test/gpr_441.cmj : cc test/gpr_441.ml | $stdlib

jscomp/test/gpr_3980_test.js

@@ -0,0 +1,48 @@
+'use strict';
+
+var Js_math = require("../../lib/js/js_math.js");
+var Caml_builtin_exceptions = require("../../lib/js/caml_builtin_exceptions.js");
+
+var match = 1;
+
+if (match !== undefined) {
+  if (match !== 1) {
+    throw [
+          Caml_builtin_exceptions.assert_failure,
+          /* tuple */[
+            "gpr_3980_test.ml",
+            16,
+            10
+          ]
+        ];
+  }
+  var match$1 = (1);
+  if (match$1 !== 1) {
+    if (match$1 !== 2) {
+      throw [
+            Caml_builtin_exceptions.assert_failure,
+            /* tuple */[
+              "gpr_3980_test.ml",
+              14,
+              12
+            ]
+          ];
+    }
+    ({
+        name: "bye",
+        age: Js_math.floor(1)
+      });
+  }
+
+} else {
+  throw [
+        Caml_builtin_exceptions.assert_failure,
+        /* tuple */[
+          "gpr_3980_test.ml",
+          16,
+          10
+        ]
+      ];
+}
+
+/*  Not a pure module */

jscomp/test/gpr_3980_test.ml

@@ -0,0 +1,16 @@
+type student = {
+  name: string;
+  age: int;
+}
+let _ =
+  match (Some 1) with
+  | Some 1 ->
+    (match [%raw "1"] with
+     | 1 -> {name = "hi"; age = 1}
+     | 2 -> {
+         name = "bye";
+         age = Js.Math.floor 1.
+       }
+     | _ -> assert false
+    ) 
+   | _ -> assert false