Fix comments

Author: RanVaknin

codegen/src/main/java/software/amazon/awssdk/codegen/AddShapes.java

@@ -311,19 +311,19 @@ private ParameterHttpMapping generateParameterHttpMapping(Shape parentShape,
 
         ParameterHttpMapping mapping = new ParameterHttpMapping();
 
-        // Per the Smithy spec, HTTP binding traits are only honored on specific shape types.
-        // When a trait is ignored, its locationName is also ignored so the member name is used as the wire name.
-        // https://smithy.io/2.0/spec/http-bindings.html
-        Location location = resolveLocation(parentShape, member, allC2jShapes);
-        boolean locationIgnored = member.getLocation() != null && location == null;
+        // Per the Smithy spec, HTTP binding traits are only honored on top-level shapes (direct operation
+        // input/output/error). When a location trait is ignored, its locationName is also ignored so the member
+        // name is used as the wire name. https://smithy.io/2.0/spec/http-bindings.html
+        Location resolvedLocation = resolveLocation(parentShape, member, allC2jShapes);
+        boolean locationIgnored = member.getLocation() != null && resolvedLocation == null;
 
         Shape memberShape = allC2jShapes.get(member.getShape());
         String marshallLocationName = locationIgnored
             ? memberName : deriveMarshallerLocationName(memberShape, memberName, member, protocol);
         String unmarshallLocationName = locationIgnored
             ? memberName : deriveUnmarshallerLocationName(memberShape, memberName, member);
 
-        mapping.withLocation(location)
+        mapping.withLocation(resolvedLocation)
                .withPayload(member.isPayload()).withStreaming(member.isStreaming())
                .withFlattened(isFlattened(member, memberShape))
                .withUnmarshallLocationName(unmarshallLocationName)
@@ -344,7 +344,7 @@ private Location resolveLocation(Shape parentShape, Member member, Map<String, S
                 return isDirectInputShape(parentShape, allC2jShapes) ? location : null;
             case HEADER:
             case HEADERS:
-                return isDirectOperationShape(parentShape, allC2jShapes) ? location : null;
+                return isTopLevelShape(parentShape, allC2jShapes) ? location : null;
             case STATUS_CODE:
                 return isDirectOutputShape(parentShape, allC2jShapes) ? location : null;
             default:
@@ -364,7 +364,7 @@ private boolean isDirectOutputShape(Shape shape, Map<String, Shape> allC2jShapes
                       .anyMatch(o -> allC2jShapes.get(o.getOutput().getShape()).equals(shape));
     }
 
-    private boolean isDirectOperationShape(Shape shape, Map<String, Shape> allC2jShapes) {
+    private boolean isTopLevelShape(Shape shape, Map<String, Shape> allC2jShapes) {
         return builder.getService().getOperations().values().stream()
                       .anyMatch(o -> (o.getInput() != null && allC2jShapes.get(o.getInput().getShape()).equals(shape))
                                      || (o.getOutput() != null && allC2jShapes.get(o.getOutput().getShape()).equals(shape))

codegen/src/test/java/software/amazon/awssdk/codegen/AddShapesTest.java

@@ -109,4 +109,12 @@ void generateShapeModel_locationNameOnNestedShape_usesMemberNameForMarshalling()
         assertThat(inputShape.findMemberModelByC2jName("NestedHeaderMember").getHttp().getMarshallLocationName()).isEqualTo("NestedHeaderMember");
     }
 
+    @Test
+    void generateShapeModel_locationNameOnTopLevelShape_honorsLocationName() {
+        ShapeModel inputShape = intermediateModel.getShapes().get("QueryParameterOperationRequest");
+        MemberModel member = inputShape.findMemberModelByC2jName("PayloadMemberWithCustomName");
+        assertThat(member.getHttp().getLocation()).isNull();
+        assertThat(member.getHttp().getMarshallLocationName()).isEqualTo("CustomWireName");
+    }
+
 }

codegen/src/test/resources/software/amazon/awssdk/codegen/poet/model/service-2.json

@@ -696,6 +696,10 @@
         "StatusCodeOnInput":{
           "shape":"Integer",
           "location":"statusCode"
+        },
+        "PayloadMemberWithCustomName":{
+          "shape":"String",
+          "locationName":"CustomWireName"
         }
       },
       "payload":"NestedQueryParameterOperation"