From e97203c3f893893611818997bbeb0116ded2605f Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Sebastian=20Dr=C3=B6ge?= Date: Wed, 21 Dec 2022 16:01:18 +0200 Subject: [PATCH] Stop at the first `NULL` argument when iterating `argv` Some C commandline parsers (e.g. GLib and Qt) are replacing already handled arguments in `argv` with `NULL` and move them to the end. That means that `argc` might be bigger than the actual number of non-`NULL` pointers in `argv` at this point. To handle this we simply stop iterating at the first `NULL` argument. `argv` is also guaranteed to be `NULL`-terminated so any non-`NULL` arguments after the first `NULL` can safely be ignored. Fixes https://github.com/rust-lang/rust/issues/105999 --- library/std/src/sys/unix/args.rs | 28 ++++++++++++++++++++++------ 1 file changed, 22 insertions(+), 6 deletions(-) diff --git a/library/std/src/sys/unix/args.rs b/library/std/src/sys/unix/args.rs index a342f0f5e8597..a5ce6d5120dad 100644 --- a/library/std/src/sys/unix/args.rs +++ b/library/std/src/sys/unix/args.rs @@ -141,12 +141,28 @@ mod imp { // list. let argv = ARGV.load(Ordering::Relaxed); let argc = if argv.is_null() { 0 } else { ARGC.load(Ordering::Relaxed) }; - (0..argc) - .map(|i| { - let cstr = CStr::from_ptr(*argv.offset(i) as *const libc::c_char); - OsStringExt::from_vec(cstr.to_bytes().to_vec()) - }) - .collect() + let mut args = Vec::with_capacity(argc as usize); + for i in 0..argc { + let ptr = *argv.offset(i) as *const libc::c_char; + + // Some C commandline parsers (e.g. GLib and Qt) are replacing already + // handled arguments in `argv` with `NULL` and move them to the end. That + // means that `argc` might be bigger than the actual number of non-`NULL` + // pointers in `argv` at this point. + // + // To handle this we simply stop iterating at the first `NULL` argument. + // + // `argv` is also guaranteed to be `NULL`-terminated so any non-`NULL` arguments + // after the first `NULL` can safely be ignored. + if ptr.is_null() { + break; + } + + let cstr = CStr::from_ptr(ptr); + args.push(OsStringExt::from_vec(cstr.to_bytes().to_vec())); + } + + args } } }