Merge pull request swiftlang#84958 from xymus/deser-witness

xymus · web-flow · commit afcbd358686f · 2025-10-20T15:11:23.000-07:00
Serialization: Fix null dereference in witness deserialization
diff --git a/lib/Serialization/Deserialization.cpp b/lib/Serialization/Deserialization.cpp
@@ -9146,7 +9146,7 @@ void ModuleFile::finishNormalConformance(NormalProtocolConformance *conformance,
 
     // Determine whether we need to enter the actor isolation of the witness.
     std::optional<ActorIsolation> enterIsolation;
-    if (*rawIDIter++) {
+    if (*rawIDIter++ && witness) {
       enterIsolation = getActorIsolation(witness);
     }
 

Original file line number	Diff line number	Diff line change
`@@ -9146,7 +9146,7 @@ void ModuleFile::finishNormalConformance(NormalProtocolConformance *conformance,`
`9146`	`9146`
`9147`	`9147`	`// Determine whether we need to enter the actor isolation of the witness.`
`9148`	`9148`	`std::optional<ActorIsolation> enterIsolation;`
`9149`		`- if (*rawIDIter++) {`
	`9149`	`+ if (*rawIDIter++ && witness) {`
`9150`	`9150`	`enterIsolation = getActorIsolation(witness);`
`9151`	`9151`	`}`
`9152`	`9152`