tests: add buf_add_char() test

...to prove off-by-one test with ASAN.

diff --git a/t/buf-simple.c b/t/buf-simple.c
index 3993ae83ab48f39ed7409c082eb5b6ea7afbd2d4..ff22aa1036dc04c68cf62e94aa3a297abc4f225d 100644 (file)
--- a/t/buf-simple.c
+++ b/t/buf-simple.c
@@ -69,11 +69,36 @@ test_buf_add_fmt(void **state)
        buf_reset(&s);
 }
 
+static void
+test_buf_add_char(void **state)
+{
+       (void)state;
+
+       const char long_string[] = "123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890";
+       size_t len = strlen(long_string);
+
+       /*
+        * Start off with a long string so that the allocated buffer is only
+        * just large enough to contain the string and the NULL termination.
+        */
+       struct buf s = BUF_INIT;
+       buf_add(&s, long_string);
+       assert_int_equal(s.alloc, len + 1);
+
+       /* Check that buf_add_char() allocates space for the new character */
+       buf_add_char(&s, '+');
+       assert_true(s.alloc >= (int)len + 2);
+       assert_string_equal(s.data + s.len - 1, "+");
+
+       buf_reset(&s);
+}
+
 int main(int argc, char **argv)
 {
        const struct CMUnitTest tests[] = {
                cmocka_unit_test(test_expand_title),
                cmocka_unit_test(test_buf_add_fmt),
+               cmocka_unit_test(test_buf_add_char),
        };
 
        return cmocka_run_group_tests(tests, NULL, NULL);