check for SyntaxKind.JSXAttribute instead of located-ness of name prop

Author: Nathan Fenner

src/compiler/checker.ts

@@ -13040,9 +13040,9 @@ namespace ts {
                                     // JsxAttributes has an object-literal flag and undergo same type-assignablity check as normal object-literal.
                                     // However, using an object-literal error message will be very confusing to the users so we give different a message.
                                     // TODO: Spelling suggestions for excess jsx attributes (needs new diagnostic messages)
-                                    if (prop.valueDeclaration && isNamedDeclaration(prop.valueDeclaration) && prop.valueDeclaration.name && prop.valueDeclaration.name.pos !== -1) {
-                                        // If the "children" attribute is extraneous `<NoChild>extra</NoChild>` then the declaration's name has no location.
-                                        // In that case, do not update the error location, since there's no name to point to.
+                                    if (prop.valueDeclaration && isJsxAttribute(prop.valueDeclaration)) {
+                                        // Note that extraneous children (as in `<NoChild>extra</NoChild>`) don't pass this check,
+                                        // since `children` is a SyntaxKind.PropertySignature instead of a SyntaxKind.JsxAttribute.
                                         errorNode = prop.valueDeclaration.name;
                                     }
                                     reportError(Diagnostics.Property_0_does_not_exist_on_type_1, symbolToString(prop), typeToString(errorTarget));