[modules] Fix crash with multiple levels of default template argument merging.

llvm-svn: 239575

2 files changed, 7 insertions, 0 deletions

diff --git a/clang/test/Modules/Inputs/submodules-merge-defs/defs.h b/clang/test/Modules/Inputs/submodules-merge-defs/defs.h
index 1ab1d1a005b..44259463a10 100644
--- a/clang/test/Modules/Inputs/submodules-merge-defs/defs.h
+++ b/clang/test/Modules/Inputs/submodules-merge-defs/defs.h
@@ -46,6 +46,7 @@ namespace G {
 
 template<typename T = int, int N = 3, template<typename> class K = F> int H(int a = 1);
 template<typename T = int, int N = 3, template<typename> class K = F> using I = decltype(H<T, N, K>());
+template<typename T = int, int N = 3, template<typename> class K = F> struct J {};
 
 namespace NS {
   struct A {};
diff --git a/clang/test/Modules/submodules-merge-defs.cpp b/clang/test/Modules/submodules-merge-defs.cpp
index 6884f56ce7d..e7c0ad7f0c1 100644
--- a/clang/test/Modules/submodules-merge-defs.cpp
+++ b/clang/test/Modules/submodules-merge-defs.cpp
@@ -40,6 +40,9 @@ int pre_ff = F<int>().f(); // expected-error +{{must be imported}}
 int pre_fg = F<int>().g<int>(); // expected-error +{{must be imported}}
 // expected-note@defs.h:26 +{{here}}
 
+J<> pre_j; // expected-error {{must be imported}} expected-error {{too few}}
+// expected-note@defs.h:49 +{{here}}
+
 // Make definitions from second module visible.
 #ifdef TEXTUAL
 #include "import-and-redefine.h"
@@ -65,3 +68,6 @@ int post_fg = F<char>().g<int>();
 // expected-error@-5 {{no matching member function}}
 // expected-note@defs.h:34 {{substitution failure}}
 #endif
+J<> post_j;
+template<typename T, int N, template<typename> class K> struct J;
+J<> post_j2;