From e97203c3f893893611818997bbeb0116ded2605f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sebastian=20Dr=C3=B6ge?= <sebastian@centricular.com>
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
}
}
}