CVE-2026-54610 LibreDWG: const-input mutation and crash in bit_TV_to_utf8 error handling

LibreDWG is a free C library to read and write DWG files. Prior to 0.14, bitTVtoutf8 in src/bits.c can write to the caller-provided src buffer despite accepting const input. On an iconv error other than E2BIG, the function frees its output buffer and passes the original input alias to bituexpand,...