Don't duplicate file descriptors into stdio fds

beetrees · beetrees · commit 0e0756cf0d1b · 2022-09-04T10:22:36.000+01:00
diff --git a/library/std/src/os/fd/owned.rs b/library/std/src/os/fd/owned.rs
@@ -104,7 +104,8 @@ impl BorrowedFd<'_> {
         #[cfg(target_os = "espidf")]
         let cmd = libc::F_DUPFD;
 
-        let fd = cvt(unsafe { libc::fcntl(self.as_raw_fd(), cmd, 0) })?;
+        // Avoid using file descriptors below 3 as they are used for stdio
+        let fd = cvt(unsafe { libc::fcntl(self.as_raw_fd(), cmd, 3) })?;
         Ok(unsafe { OwnedFd::from_raw_fd(fd) })
     }
 

Original file line number	Diff line number	Diff line change
`@@ -104,7 +104,8 @@ impl BorrowedFd<'_> {`
`104`	`104`	`#[cfg(target_os = "espidf")]`
`105`	`105`	`let cmd = libc::F_DUPFD;`
`106`	`106`
`107`		`- let fd = cvt(unsafe { libc::fcntl(self.as_raw_fd(), cmd, 0) })?;`
	`107`	`+ // Avoid using file descriptors below 3 as they are used for stdio`
	`108`	`+ let fd = cvt(unsafe { libc::fcntl(self.as_raw_fd(), cmd, 3) })?;`
`108`	`109`	`Ok(unsafe { OwnedFd::from_raw_fd(fd) })`
`109`	`110`	`}`
`110`	`111`