Add test for include.path inside included config

It fails at least on my computer, though it may depend on some unpredictable
factors (say, will realloc() extend the memory segment in place, or it will
allocate new memory).

tests/config/include.c

@@ -102,3 +102,25 @@ void test_config_include__missing(void)
 
 	git_config_free(cfg);
 }
+
+#define replicate10(s) s s s s s s s s s s
+void test_config_include__depth2(void)
+{
+	git_config *cfg;
+	const char *str;
+	const char *content = "[include]\n" replicate10(replicate10("path=bottom\n"));
+
+	cl_git_mkfile("top-level", "[include]\npath = middle\n[foo]\nbar = baz");
+	cl_git_mkfile("middle", content);
+	cl_git_mkfile("bottom", "[foo]\nbar2 = baz2");
+
+	cl_git_pass(git_config_open_ondisk(&cfg, "top-level"));
+
+	cl_git_pass(git_config_get_string(&str, cfg, "foo.bar"));
+	cl_assert_equal_s(str, "baz");
+
+	cl_git_pass(git_config_get_string(&str, cfg, "foo.bar2"));
+	cl_assert_equal_s(str, "baz2");
+
+	git_config_free(cfg);
+}