[Concepts] Fix crash in D41910

Differential Revision: https://reviews.llvm.org/D41910
llvm · Dec 18, 2019 · 12038be · 12038be
1 parent c7abf88
commit 12038be
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/clang/lib/Sema/SemaConcept.cpp b/clang/lib/Sema/SemaConcept.cpp
@@ -558,7 +558,7 @@ static bool substituteParameterMappings(Sema &S, NormalizedConstraint &N,
     Atomic.ParameterMapping.emplace();
     Atomic.ParameterMapping->reserve(OccurringIndices.size());
     for (unsigned I = 0, C = TemplateParams->size(); I != C; ++I)
-      if (OccurringIndices[I])
+      if (I < OccurringIndices.size() && OccurringIndices[I])
         Atomic.ParameterMapping->push_back(
             S.getIdentityTemplateArgumentLoc(TemplateParams->begin()[I],
                 // Here we assume we do not support things like