fix: Move off atty to resolve soundness issue

There is a soundness issue with atty when building on Windows with a
custom allocator.

This PR switches direct dependencies on atty to is-terminal.  New semver
compatible versions of clap and snapbox remove atty. rust-lang#11417 upgrades
env_logger to remove it from there.

Fixes rust-lang#11415

Cargo.toml

@@ -16,7 +16,7 @@ name = "cargo"
 path = "src/cargo/lib.rs"
 
 [dependencies]
-atty = "0.2"
+is-terminal = "0.4.0"
 bytesize = "1.0"
 cargo-platform = { path = "crates/cargo-platform", version = "0.1.2" }
 cargo-util = { path = "crates/cargo-util", version = "0.2.3" }

crates/resolver-tests/Cargo.toml

@@ -9,4 +9,4 @@ cargo-util = { path = "../cargo-util" }
 proptest = "0.9.1"
 lazy_static = "1.3.0"
 varisat = "0.2.1"
-atty = "0.2.11"
+is-terminal = "0.4.0"

crates/resolver-tests/tests/resolve.rs

@@ -21,7 +21,7 @@ use proptest::prelude::*;
 proptest! {
     #![proptest_config(ProptestConfig {
         max_shrink_iters:
-            if is_ci() || !atty::is(atty::Stream::Stderr) {
+            if is_ci() || !is_terminal::IsTerminal::is_terminal(std::io::stderr()){
                 // This attempts to make sure that CI will fail fast,
                 0
             } else {

src/cargo/core/shell.rs

@@ -1,6 +1,7 @@
 use std::fmt;
 use std::io::prelude::*;
 
+use is_terminal::IsTerminal;
 use termcolor::Color::{Cyan, Green, Red, Yellow};
 use termcolor::{self, Color, ColorSpec, StandardStream, WriteColor};
 
@@ -99,14 +100,10 @@ impl Shell {
         let auto_clr = ColorChoice::CargoAuto;
         Shell {
             output: ShellOut::Stream {
-                stdout: StandardStream::stdout(
-                    auto_clr.to_termcolor_color_choice(atty::Stream::Stdout),
-                ),
-                stderr: StandardStream::stderr(
-                    auto_clr.to_termcolor_color_choice(atty::Stream::Stderr),
-                ),
+                stdout: StandardStream::stdout(auto_clr.to_termcolor_color_choice(Stream::Stdout)),
+                stderr: StandardStream::stderr(auto_clr.to_termcolor_color_choice(Stream::Stderr)),
                 color_choice: ColorChoice::CargoAuto,
-                stderr_tty: atty::is(atty::Stream::Stderr),
+                stderr_tty: std::io::stderr().is_terminal(),
             },
             verbosity: Verbosity::Verbose,
             needs_clear: false,
@@ -301,8 +298,8 @@ impl Shell {
                 ),
             };
             *color_choice = cfg;
-            *stdout = StandardStream::stdout(cfg.to_termcolor_color_choice(atty::Stream::Stdout));
-            *stderr = StandardStream::stderr(cfg.to_termcolor_color_choice(atty::Stream::Stderr));
+            *stdout = StandardStream::stdout(cfg.to_termcolor_color_choice(Stream::Stdout));
+            *stderr = StandardStream::stderr(cfg.to_termcolor_color_choice(Stream::Stderr));
         }
         Ok(())
     }
@@ -496,12 +493,12 @@ impl ShellOut {
 
 impl ColorChoice {
     /// Converts our color choice to termcolor's version.
-    fn to_termcolor_color_choice(self, stream: atty::Stream) -> termcolor::ColorChoice {
+    fn to_termcolor_color_choice(self, stream: Stream) -> termcolor::ColorChoice {
         match self {
             ColorChoice::Always => termcolor::ColorChoice::Always,
             ColorChoice::Never => termcolor::ColorChoice::Never,
             ColorChoice::CargoAuto => {
-                if atty::is(stream) {
+                if stream.is_terminal() {
                     termcolor::ColorChoice::Auto
                 } else {
                     termcolor::ColorChoice::Never
@@ -511,6 +508,20 @@ impl ColorChoice {
     }
 }
 
+enum Stream {
+    Stdout,
+    Stderr,
+}
+
+impl Stream {
+    fn is_terminal(self) -> bool {
+        match self {
+            Self::Stdout => std::io::stdout().is_terminal(),
+            Self::Stderr => std::io::stderr().is_terminal(),
+        }
+    }
+}
+
 #[cfg(unix)]
 mod imp {
     use super::{Shell, TtyWidth};