Fix crash with missing name in span in debug mode (#2893)

Signed-off-by: Bob Weinand <[email protected]>

Author: bwoebi

ext/serializer.c

@@ -1752,7 +1752,7 @@ void ddtrace_serialize_span_to_array(ddtrace_span_data *span, zval *array) {
         prop_name = zend_hash_str_find(Z_ARR_P(el), ZEND_STRL("name")); // refetch, array may have been rehashed
         log("Encoding span %" PRIu64 ": trace_id=%s, name='%s', service='%s', resource: '%s', type '%s' with tags: %s; and metrics: %s",
             span->span_id,
-            Z_STRVAL(span->root->property_trace_id), Z_TYPE_P(prop_name) == IS_STRING ? Z_STRVAL_P(prop_name) : "",
+            Z_STRVAL(span->root->property_trace_id), prop_name && Z_TYPE_P(prop_name) == IS_STRING ? Z_STRVAL_P(prop_name) : "",
             Z_TYPE(prop_service_as_string) == IS_STRING ? Z_STRVAL(prop_service_as_string) : "",
             Z_TYPE(prop_resource_as_string) == IS_STRING ? Z_STRVAL(prop_resource_as_string) : "",
             Z_TYPE(prop_type_as_string) == IS_STRING ? Z_STRVAL(prop_type_as_string) : "",