get_fullpath produces path prefixed with "//" when the first arg "/"

[CorsacFox-hub]

sfm.c lines 332 to 335

if (first[0] == '/' && first[1] == '\0')
   (void)snprintf(full_path, PATH_MAX, "/%s", second);

ret = snprintf(full_path, PATH_MAX, "%s/%s", first, second);

If variable first is string "/" then the result of first special case snprintf , which is placed in the buffer full_path, will be over-written by the second snprintf, so in that case the first snprintf will have no effect, so if first is "/" the full_path will start with "//" which presumably the code was meant to be avoided. Also the result of the first snprintf is not checked (I overlooked that in my first raising of this issue).

May I suggest

if (first[0] == '/' && first[1] == '\0')
     ret = snprintf(full_path, PATH_MAX, "/%s", second);
else
     ret = snprintf(full_path, PATH_MAX, "%s/%s", first, second);

Then both snprintf will produce a ret value and drop through to the subsequent validation of the ret value.