Merge pull request #31961 from CodaFi/setternalia

Author: swift-ci

lib/Sema/TypeCheckProtocol.cpp

@@ -2338,8 +2338,9 @@ diagnoseMatch(ModuleDecl *module, NormalProtocolConformance *conformance,
         diags.diagnose(witness, diag::protocol_witness_settable_conflict);
     if (auto VD = dyn_cast<VarDecl>(witness)) {
       if (VD->hasStorage()) {
-        auto PBD = VD->getParentPatternBinding();
-        diag.fixItReplace(PBD->getStartLoc(), getTokenText(tok::kw_var));
+        if (auto PBD = VD->getParentPatternBinding()) {
+          diag.fixItReplace(PBD->getStartLoc(), getTokenText(tok::kw_var));
+        }
       }
     }
     break;

test/decl/protocol/req/Inputs/witness_fix_its_other_module.swift

@@ -0,0 +1,7 @@
+public protocol OtherOS {
+  var name: String { get }
+}
+
+public struct Linux: OtherOS {
+  public let name = "Linux"
+}

test/decl/protocol/req/witness_fix_its.swift

@@ -1,8 +1,12 @@
-// RUN: %target-typecheck-verify-swift
+// RUN: %empty-directory(%t)
+// RUN: %target-swift-frontend -emit-module -o %t/OtherOS.swiftmodule -module-name OtherOS %S/Inputs/witness_fix_its_other_module.swift -parse-as-library
+// RUN: %target-typecheck-verify-swift -I %t/
 
 prefix operator ^^^
 postfix operator ^^^^
 
+import OtherOS
+
 protocol Foo {
   var bar1: Int { get set } // expected-note {{protocol requires property 'bar1' with type 'Int'; do you want to add a stub?}}
   static var bar2: Int { get set } // expected-note {{protocol requires property 'bar2' with type 'Int'; do you want to add a stub?}}
@@ -34,3 +38,12 @@ protocol Foo1 {
 struct ConformsToFoo1: Foo1 { // expected-error {{type 'ConformsToFoo1' does not conform to protocol 'Foo1'}}
   subscript(value: Bool) -> Bool { return false } // expected-note {{candidate is not settable, but protocol requires it}}{{none}}
 }
+
+// Don't crash or try to fixup get/set mismatches in other modules
+// This protocol requirement must conflict with the one in
+// witness_fix_its_other_module.swift.
+protocol RenameableProtocol {
+  var name: String { get set } // expected-note {{protocol requires property 'name' with type 'String'; do you want to add a stub?}}
+}
+
+extension Linux: RenameableProtocol {} // expected-error {{type 'Linux' does not conform to protocol 'RenameableProtocol'}}