[clang] [clang][ASTImporter] Fix import of variable template redeclarations. (PR #72841)

[Balázs Kéri via cfe-commits]

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@@ -6245,17 +6245,21 @@ ExpectedDecl ASTNodeImporter::VisitVarTemplateDecl(VarTemplateDecl *D) {
                                               D->getTemplatedDecl()))
         continue;
       if (IsStructuralMatch(D, FoundTemplate)) {
-        // The Decl in the "From" context has a definition, but in the
-        // "To" context we already have a definition.
+        // FIXME Check for ODR error if the two definitions have
+        // different initializers?
         VarTemplateDecl *FoundDef = getTemplateDefinition(FoundTemplate);
-        if (D->isThisDeclarationADefinition() && FoundDef)
-          // FIXME Check for ODR error if the two definitions have
-          // different initializers?
-          return Importer.MapImported(D, FoundDef);
-        if (FoundTemplate->getDeclContext()->isRecord() &&
-            D->getDeclContext()->isRecord())
-          return Importer.MapImported(D, FoundTemplate);
-
+        if (D->getDeclContext()->isRecord()) {
+          assert(FoundTemplate->getDeclContext()->isRecord() &&
+                 "Member variable template imported as non-member, "
+                 "inconsistent imported AST?");
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balazske wrote:

The existing "To" AST can be somehow invalid or declarations can be in wrong scope, because previous wrong AST imports and structural equivalence problems, or here a wrong declaration may be found. This assertion looks to check for such problems (check `FoundTemplate->getDeclContext()->isRecord()` if `D->getDeclContext()->isRecord()`).

https://github.com/llvm/llvm-project/pull/72841