[clang] [Clang] Prevent null pointer dereference in Sema::​CodeCompleteQualifiedId() (PR #90490)

[Shafik Yaghmour via cfe-commits]

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@@ -6714,14 +6714,16 @@ void Sema::CodeCompleteQualifiedId(Scope *S, CXXScopeSpec &SS,
 
   // If the scope is a concept-constrained type parameter, infer nested
   // members based on the constraints.
-  if (const auto *TTPT =
-          dyn_cast_or_null<TemplateTypeParmType>(NNS->getAsType())) {
-    for (const auto &R : ConceptInfo(*TTPT, S).members()) {
-      if (R.Operator != ConceptInfo::Member::Colons)
-        continue;
-      Results.AddResult(CodeCompletionResult(
-          R.render(*this, CodeCompleter->getAllocator(),
-                   CodeCompleter->getCodeCompletionTUInfo())));
+  if (NNS) {
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shafik wrote:

This looks good, We can even seen above `NNS` is checked before access. This looks like an unfortunate oversight.

https://github.com/llvm/llvm-project/pull/90490