[nullability] Fix crash on function template calls that only deduce some arguments.

PiperOrigin-RevId: 527531959

nullability_verification/test/function_calls.cc

diff --git a/nullability_verification/test/function_calls.cc b/nullability_verification/test/function_calls.cc
index effa853..e64a6da 100644
--- a/nullability_verification/test/function_calls.cc
+++ b/nullability_verification/test/function_calls.cc
@@ -435,6 +435,14 @@
   )cc"));
 }
 
+TEST(PointerNullabilityTest, CallFunctionTemplate_PartiallyDeduced) {
+  EXPECT_TRUE(checkDiagnostics(R"cc(
+    template <int, class T>
+    T f(T);
+    void target() { f<0>(1); }
+  )cc"));
+}
+
 }  // namespace
 }  // namespace nullability
 }  // namespace tidy