---

yaml
---
r: 348601
b: refs/heads/master
c: 6d6e347
h: refs/heads/master
i:
  348599: 5bcfb15

Author: swift-ci

[refs]

@@ -1,5 +1,5 @@
 ---
-refs/heads/master: f0d946690f079f34b8098e74436f8d5b106fbc9a
+refs/heads/master: 6d6e3477a84996c2bbf1ae9717e81a09233af63c
 refs/heads/master-next: 203b3026584ecad859eb328b2e12490099409cd5
 refs/tags/osx-passed: b6b74147ef8a386f532cf9357a1bde006e552c54
 refs/tags/swift-2.2-SNAPSHOT-2015-12-01-a: 6bb18e013c2284f2b45f5f84f2df2887dc0f7dea

trunk/lib/AST/SubstitutionMap.cpp

@@ -388,12 +388,15 @@ SubstitutionMap::lookupConformance(CanType type, ProtocolDecl *proto) const {
     if (conformance->isAbstract()) {
       // FIXME: Rip this out once we can get a concrete conformance from
       // an archetype.
-      auto *M = proto->getParentModule();
       auto substType = type.subst(*this);
+      if (substType->hasError())
+        return ProtocolConformanceRef(proto);
+
       if ((!substType->is<ArchetypeType>() ||
            substType->castTo<ArchetypeType>()->getSuperclass()) &&
           !substType->isTypeParameter() &&
           !substType->isExistentialType()) {
+        auto *M = proto->getParentModule();
         return M->lookupConformance(substType, proto);
       }
 

trunk/validation-test/compiler_crashers_2_fixed/0206-rdar54952911.swift

@@ -0,0 +1,49 @@
+// RUN: %target-swift-frontend -emit-silgen %s
+// FIXME: Get the above to pass with -emit-ir too.
+
+public protocol P1 {
+    associatedtype A1: P3 where A1.A4.A3: P6
+}
+
+public protocol P12 : P1 where A1: P2 {}
+
+public protocol P2 : P3 where A3 == S3<A2>, A4: P4 {}
+
+public protocol P4 : P3 where A3 == S2<A2>, A4: P5 {}
+
+public protocol P5: P9 where A3 == S1<A2> {}
+
+public protocol P6: P11 where A2: P7 {}
+
+public protocol P7: P8 {}
+
+public protocol P8 {}
+
+public protocol P11 {
+	associatedtype A2 : P8
+}
+
+public struct S1<A2 : P8> : P11 {}
+
+public struct S2<A2 : P8> : P11 {}
+
+extension S2: P6 where A2: P7 {}
+
+public struct S3<A2 : P8> : P11 {}
+
+public protocol P9 {
+    associatedtype A2: P7
+    associatedtype A3: P11 where A3.A2 == A2
+}
+
+public protocol P3 : P9 {
+    associatedtype A4: P9 where A4.A2 == A2
+}
+
+public protocol P10 {
+    associatedtype A3: P11 where A3.A2: P7
+}
+
+public struct S4<T: P12> : P10 {
+    public typealias A3 = T.A1.A4.A3
+}