Add regression test for #10473 (#3457)

Author: chrchr-github

test/testautovariables.cpp

@@ -149,6 +149,7 @@ class TestAutoVariables : public TestFixture {
         TEST_CASE(danglingTemporaryLifetime);
         TEST_CASE(invalidLifetime);
         TEST_CASE(deadPointer);
+        TEST_CASE(splitNamespaceAuto); // crash #10473
     }
 
 
@@ -3194,6 +3195,18 @@ class TestAutoVariables : public TestFixture {
         ASSERT_EQUALS("[test.cpp:5] -> [test.cpp:4] -> [test.cpp:8]: (error) Using pointer to local variable 'x' that is out of scope.\n", errout.str());
     }
 
+    void splitNamespaceAuto() { // #10473
+        check("namespace ns\n"
+              "{\n"
+              "    auto var{ 0 };\n"
+              "}\n"
+              "namespace ns\n"
+              "{\n"
+              "    int i;\n"
+              "}\n");
+        ASSERT_EQUALS("", errout.str());
+    }
+
 };
 
 REGISTER_TEST(TestAutoVariables)