Be more robust against printf failures
If an 'output error' is encountered, vsnprintf() will return -1, causing g_printf_string_upper_bound() to return 0. Handle this case in g_vasprintf() without crashing.
Fixes: #3187 (closed)
If an 'output error' is encountered, vsnprintf() will return -1, causing g_printf_string_upper_bound() to return 0. Handle this case in g_vasprintf() without crashing.
Fixes: #3187 (closed)