[Sema] Fix assumption about typo corrections containing no decl.

This can happen when the typo correction is coming from an external sema
source. Test case will follow in clang-tools-extra.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@292927 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 6 insertions, 3 deletions

diff --git a/lib/Sema/SemaDeclCXX.cpp b/lib/Sema/SemaDeclCXX.cpp
index f265f4c00f..671d3251a5 100644
--- a/lib/Sema/SemaDeclCXX.cpp
+++ b/lib/Sema/SemaDeclCXX.cpp
@@ -9169,15 +9169,18 @@ NamedDecl *Sema::BuildUsingDeclaration(Scope *S, AccessSpecifier AS,
                 HasTypenameKeyword, IsInstantiation, SS.getScopeRep(),
                 dyn_cast<CXXRecordDecl>(CurContext)),
             CTK_ErrorRecovery)) {
-      // We reject any correction for which ND would be NULL.
-      NamedDecl *ND = Corrected.getCorrectionDecl();
-
       // We reject candidates where DroppedSpecifier == true, hence the
       // literal '0' below.
       diagnoseTypo(Corrected, PDiag(diag::err_no_member_suggest)
                                 << NameInfo.getName() << LookupContext << 0
                                 << SS.getRange());
 
+      // If we picked a correction with no attached Decl we can't do anything
+      // useful with it, bail out.
+      NamedDecl *ND = Corrected.getCorrectionDecl();
+      if (!ND)
+        return BuildInvalid();
+
       // If we corrected to an inheriting constructor, handle it as one.
       auto *RD = dyn_cast<CXXRecordDecl>(ND);
       if (RD && RD->isInjectedClassName()) {