Add bxs_last_char_ptr() in bxstring module

src/bxstring.c

@@ -366,6 +366,16 @@ uint32_t *bxs_first_char_ptr(bxstr_t *pString, size_t n)
 
 
 
+uint32_t *bxs_last_char_ptr(bxstr_t *pString)
+{
+    if (pString == NULL) {
+        return NULL;
+    }
+    return pString->memory + pString->first_char[pString->num_chars_visible];
+}
+
+
+
 uint32_t *bxs_unindent_ptr(bxstr_t *pString)
 {
     if (pString == NULL) {

src/bxstring.h

@@ -163,6 +163,14 @@ bxstr_t *bxs_cut_front(bxstr_t *pString, size_t n);
 uint32_t *bxs_first_char_ptr(bxstr_t *pString, size_t n);
 
 
+/**
+ * Return a pointer to the NUL terminator of the given string's `memory`.
+ * @param pString the string to use
+ * @return a pointer into existing memory
+ */
+uint32_t *bxs_last_char_ptr(bxstr_t *pString);
+
+
 /**
  * Return the first character of the visible character directly following the indent (for example a letter following
  * some spaces).

utest/bxstring_test.c

@@ -487,6 +487,26 @@ void test_bxs_cut_front_zero(void **state)
 
 
 
+void test_bxs_last_char_ptr(void **state)
+{
+    UNUSED(state);
+
+    uint32_t *ustr32 = u32_strconv_from_arg("abc", "ASCII");
+    assert_non_null(ustr32);
+    bxstr_t *input = bxs_from_unicode(ustr32);
+
+    assert_null(bxs_last_char_ptr(NULL));
+
+    uint32_t *actual = bxs_last_char_ptr(input);
+    assert_true(*actual == char_nul);
+    assert_int_equal(3, actual - input->memory);
+
+    BFREE(ustr32);
+    bxs_free(input);
+}
+
+
+
 void test_bxs_trimdup_null(void **state)
 {
     UNUSED(state);

utest/bxstring_test.h

@@ -45,6 +45,8 @@ void test_bxs_strdup(void **state);
 void test_bxs_cut_front(void **state);
 void test_bxs_cut_front_zero(void **state);
 
+void test_bxs_last_char_ptr(void **state);
+
 void test_bxs_trimdup_null(void **state);
 void test_bxs_trimdup_invalid_startidx(void **state);
 void test_bxs_trimdup_invalid_endidx(void **state);

utest/main.c

@@ -139,6 +139,7 @@ int main(void)
         cmocka_unit_test_setup(test_bxs_strdup, beforeTest),
         cmocka_unit_test_setup(test_bxs_cut_front, beforeTest),
         cmocka_unit_test_setup(test_bxs_cut_front_zero, beforeTest),
+        cmocka_unit_test_setup(test_bxs_last_char_ptr, beforeTest),
         cmocka_unit_test_setup(test_bxs_trimdup_null, beforeTest),
         cmocka_unit_test_setup(test_bxs_trimdup_invalid_startidx, beforeTest),
         cmocka_unit_test_setup(test_bxs_trimdup_invalid_endidx, beforeTest),