bzip2recover: Check argc >= 1 && argv[0] != NULL

main() initialises progName by copying argv[0] with strncpy before argc
is examined. When the program is started with an empty argument vector
(argc == 0 and argv[0] == NULL), for example through
execve(path, (char*[]){ NULL }, envp), this dereferences a NULL pointer
and bzip2recover crashes with SIGSEGV before any argument checking
happens.

Guard the use of argv[0] and fall back to a hard coded "bzip2recover"
string, mirroring the fix already applied to bzip2.c in commit
af79253677ad ("bzip2.c: Check argc >= 1 && argv[0] != NULL").

0 files changed, 0 insertions, 0 deletions