The `ignore_malformed` option is supported by a few of our field types, mainly numerics and dates, to still accept the document when such fields hold malformed values. See https://www.elastic.co/guide/en/elasticsearch/reference/current/ignore-malformed.html. Also `ignore_malformed` is an index level setting that gets applied to all field types that support it. 

The boolean field type does not support `ignore_malformed` but it should, so that if a boolean field cannot be parsed as a boolean, the document can still be accepted.


server/src/main/java/org/elasticsearch/index/mapper/DynamicFieldsBuilder.java
);
        }
        @Override
        public void newDynamicDateField(DocumentParserContext context, String name, DateFormatter dateTimeFormatter) throws IOException {
            Settings settings = context.indexSettings().getSettings();
            boolean ignoreMalformed = FieldMapper.IGNORE_MALFORMED_SETTING.get(settings);
            createDynamicField(
                new DateFieldMapper.Builder(
                    name,
                    DateFieldMapper.Resolution.MILLISECONDS,
                    dateTimeFormatter,
                    ScriptCompiler.NONE,
                    ignoreMalformed,
                    context.indexSettings().getIndexVersionCreated()
                ),
                context
            );
        }
        void newDynamicBinaryField(DocumentParserContext context, String name) throws IOException {
            createDynamicField(new BinaryFieldMapper.Builder(name), context);
        }
    }
    /**
     * Dynamically creates runtime fields, in the runtime section.
     * Used for sub-fields of objects that are mapped as dynamic:runtime.
     * @see Dynamic
     */
    private static final class Runtime implements Strategy {
        static void createDynamicField(RuntimeField runtimeField, DocumentParserContext context) {
            context.addDynamicRuntimeField(runtimeField);