add no_auto_head option in app route decorator

src/flask/app.py

@@ -1046,6 +1046,7 @@ class Flask(Scaffold):
             endpoint = _endpoint_from_view_func(view_func)  # type: ignore
         options["endpoint"] = endpoint
         methods = options.pop("methods", None)
+        no_auto_head = options.pop("no_auto_head", None)
 
         # if the methods are not given and the view_func object knows its
         # methods we can use that instead.  If neither exists, we go with
@@ -1082,6 +1083,14 @@ class Flask(Scaffold):
         rule = self.url_rule_class(rule, methods=methods, **options)
         rule.provide_automatic_options = provide_automatic_options  # type: ignore
 
+        # If GET is only specified method, Werkzeug automatically adds HEAD method.
+        # This option will disable that feature to allow the user to write their
+        # own handling for HEAD.
+        only_get = methods == {"GET", "OPTIONS"}
+
+        if only_get and no_auto_head is not None:
+            rule.methods.discard("HEAD")
+
         self.url_map.add(rule)
         if view_func is not None:
             old_func = self.view_functions.get(endpoint)

tests/test_basic.py

@@ -2024,3 +2024,16 @@ def test_app_freed_on_zero_refcount():
         assert weak() is None
     finally:
         gc.enable()
+
+
+def test_no_auto_head_option(app, client):
+    @app.route("/", methods=["GET"], no_auto_head=True)
+    def index():
+        return "Hello world", 200
+
+    @app.route("/", methods=["HEAD"])
+    def index_head():
+        return "", 200, {"test-header": "test-value"}
+
+    assert client.get("/").data == b"Hello world"
+    assert "test-header" in client.head("/").headers