Get Tracer operation should use an empty string if the specified name is null (#1654)

Author: carlosalberto

CHANGELOG.md

@@ -14,6 +14,8 @@ release.
 
 ### Traces
 
+- `Get Tracer` should use an empty string if the specified `name` is null. ([#1654](https://github.com/open-telemetry/opentelemetry-specification/pull/1654))
+
 ### Metrics
 
 ### Logs

specification/trace/api.md

@@ -110,7 +110,7 @@ This API MUST accept the following parameters:
   or application.
   In case an invalid name (null or empty string) is specified, a working
   Tracer implementation MUST be returned as a fallback rather than returning
-  null or throwing an exception, its `name` property SHOULD keep the original invalid value,
+  null or throwing an exception, its `name` property SHOULD be set to an **empty** string,
   and a message reporting that the specified value is invalid SHOULD be logged.
   A library, implementing the OpenTelemetry API *may* also ignore this name and
   return a default instance for all calls, if it does not support "named"