[IDE] Fix assertion failure in PostfixCompletionCallback::Result::tryMerge

Unfortunately due to pre-checking multiple times the recorded
application level can change. Just OR the bits together.

Author: hamishknight

lib/IDE/PostfixCompletion.cpp

@@ -27,8 +27,7 @@ bool PostfixCompletionCallback::Result::tryMerge(const Result &Other,
   if (BaseDecl != Other.BaseDecl)
     return false;
 
-  // These properties should match if we are talking about the same BaseDecl.
-  assert(IsBaseDeclUnapplied == Other.IsBaseDeclUnapplied);
+  // This should match if we are talking about the same BaseDecl.
   assert(BaseIsStaticMetaType == Other.BaseIsStaticMetaType);
 
   auto baseTy = tryMergeBaseTypeForCompletionLookup(BaseTy, Other.BaseTy, DC);
@@ -56,6 +55,12 @@ bool PostfixCompletionCallback::Result::tryMerge(const Result &Other,
   ExpectsNonVoid &= Other.ExpectsNonVoid;
   IsImpliedResult |= Other.IsImpliedResult;
   IsInAsyncContext |= Other.IsInAsyncContext;
+
+  // Note this may differ if we pre-check multiple times since pre-checking
+  // changes the recorded apply level.
+  // FIXME: We ought to fix completion to not pre-check multiple times.
+  IsBaseDeclUnapplied |= Other.IsBaseDeclUnapplied;
+
   return true;
 }
 

validation-test/IDE/crashers/700c7172dd0e486.swift renamed to validation-test/IDE/crashers_fixed/700c7172dd0e486.swift

@@ -1,3 +1,3 @@
 // {"kind":"complete","signature":"swift::ide::PostfixCompletionCallback::Result::tryMerge(swift::ide::PostfixCompletionCallback::Result const&, swift::DeclContext*)"}
-// RUN: not --crash %target-swift-ide-test -code-completion --code-completion-token=COMPLETE -code-completion-diagnostics -source-filename %s
+// RUN: %target-swift-ide-test -code-completion --code-completion-token=COMPLETE -code-completion-diagnostics -source-filename %s
 Int { switch { case Optional.some()#^COMPLETE^#

validation-test/IDE/issues_fixed/issue-75845.swift

@@ -15,3 +15,28 @@ struct Foo {
 // B: Begin completions
 // C: Decl[LocalVar]/Local: error[#any Error#]; name=error
 // D: Begin completions
+
+enum E {
+  case e(Error)
+
+  func foo() {
+    var x = self
+    do {
+    } catch {
+      x = .e(error)#^E^#
+      // E: Decl[InstanceMethod]/CurrNominal/TypeRelation[Invalid]: .foo()[#Void#]; name=foo()
+    }
+  }
+
+  static func bar() {
+    do {
+    } catch {
+      _ = foo(.e(error))#^F^#
+      // F: Decl[InstanceMethod]/CurrNominal/Flair[ArgLabels]: ()[#Void#]; name=()
+
+      _ = foo(.e(error))()#^G^#
+      // G: Begin completions, 1 items
+      // G: Keyword[self]/CurrNominal: .self[#Void#]; name=self
+    }
+  }
+}