Do not write a value in Context upon failed extraction. (open-telemet…

…ry#671)
codeboten · Jul 20, 2020 · 3cdc2f0 · 3cdc2f0
1 parent c414835
commit 3cdc2f0
Showing 1 changed file with 2 additions and 2 deletions.
diff --git a/specification/context/api-propagators.md b/specification/context/api-propagators.md
@@ -105,8 +105,8 @@ The implemenation SHOULD preserve casing (e.g. it should not transform `Content-
 Extracts the value from an incoming request. For example, from the headers of an HTTP request.
 
 If a value can not be parsed from the carrier for a cross-cutting concern,
-the implementation MUST NOT throw an exception. It MUST store a value in the `Context`
-that the implementation can recognize as a null or empty value.
+the implementation MUST NOT throw an exception and MUST NOT store a new value in the `Context`,
+in order to preserve any previously existing valid value.
 
 Required arguments: