2 files changed, 22 insertions(+), 7 deletions(-)

M astr.c
M astr_tests.c

@@ 83,7 83,7 @@ astr_realloc_append_formatted_from_va_list(char **s,
     size_t length_to_append = astr_formatted_length_from_va_list(format, arguments);
     if (!length_to_append) return 0;
 
-    size_t original_length = strlen(*s);
+    size_t original_length = *s ? strlen(*s) : 0;
     size_t new_size = original_length + length_to_append + sizeof('\0');
     char *resized_s = realloc(*s, new_size);
     if (!resized_s) return -1;

@@ 26,7 26,7 @@ test_astr_alloc_formatted(void)
 
 
 static void
-test_astr_alloc_formatted_for_NULL_format(void)
+test_astr_alloc_formatted_for_invalid_format(void)
 {
     errno = 0;
     char *s = astr_alloc_formatted(NULL);


@@ 117,7 117,7 @@ test_astr_formatted_length(void)
 
 
 static void
-test_astr_formatted_length_for_NULL_format(void)
+test_astr_formatted_length_for_invalid_format(void)
 {
     errno = 0;
     size_t length = astr_formatted_length(NULL);


@@ 157,6 157,20 @@ test_astr_realloc_append_formatted_for_empty_format(void)
 static void
 test_astr_realloc_append_formatted_for_NULL_string(void)
 {
+    char *s = NULL;
+
+    int result = astr_realloc_append_formatted(&s, "bar %i", 42);
+
+    assert(0 == result);
+    assert(s);
+    assert(astr_eq("bar 42", s));
+    free(s);
+}
+
+
+static void
+test_astr_realloc_append_formatted_for_invalid_string_pointer(void)
+{
     errno = 0;
     int result = astr_realloc_append_formatted(NULL, "foobar");
 


@@ 166,7 180,7 @@ test_astr_realloc_append_formatted_for_NULL_string(void)
 
 
 static void
-test_astr_realloc_append_formatted_for_NULL_format(void)
+test_astr_realloc_append_formatted_for_invalid_format(void)
 {
     char *s = astr_alloc_formatted("foo");
 


@@ 184,17 198,18 @@ main(int argc, char *argv[])
 {
     test_astr_alloc_empty();
     test_astr_alloc_formatted();
-    test_astr_alloc_formatted_for_NULL_format();
+    test_astr_alloc_formatted_for_invalid_format();
     test_astr_cmp();
     test_astr_empty();
     test_astr_eq();
     test_astr_eq_for_NULL_string();
     test_astr_eq_for_empty_strings();
     test_astr_formatted_length();
-    test_astr_formatted_length_for_NULL_format();
+    test_astr_formatted_length_for_invalid_format();
     test_astr_realloc_append_formatted_for_empty_format();
     test_astr_realloc_append_formatted_for_NULL_string();
-    test_astr_realloc_append_formatted_for_NULL_format();
+    test_astr_realloc_append_formatted_for_invalid_string_pointer();
+    test_astr_realloc_append_formatted_for_invalid_format();
     return EXIT_SUCCESS;
 }