Add two tests for --background

Author: bjorn3

src/exec/use_pty/parent.rs

@@ -60,7 +60,7 @@ pub(in crate::exec) fn exec_pty(
     // `policy_init_session`.
     // FIXME (ogsudo): initializes ttyblock sigset here by calling `init_ttyblock`
 
-    // Fetch the parent process group so we can signals to it.
+    // Fetch the parent process group so we can send signals to it.
     let parent_pgrp = getpgrp();
 
     // Set all the IO streams for the command to the follower side of the pty.

test-framework/sudo-compliance-tests/src/sudo.rs

@@ -3,6 +3,7 @@ mod apparmor;
 mod child_process;
 mod cli;
 mod env_reset;
+mod flag_background;
 mod flag_chdir;
 mod flag_group;
 mod flag_help;

test-framework/sudo-compliance-tests/src/sudo/flag_background.rs

@@ -0,0 +1,62 @@
+use sudo_test::{Command, Env};
+
+use crate::SUDOERS_ALL_ALL_NOPASSWD;
+
+#[test]
+fn runs_in_background() {
+    let env = Env(SUDOERS_ALL_ALL_NOPASSWD).build();
+
+    Command::new("sudo")
+        .args([
+            "-b",
+            "sh",
+            "-c",
+            "touch /tmp/barrier1; until [ -f /tmp/barrier2 ]; do sleep 0.1; done; touch /tmp/barrier3",
+        ])
+        .output(&env)
+        .assert_success();
+
+    Command::new("sh")
+        .args([
+            "-c",
+            "until [ -f /tmp/barrier1 ]; do sleep 0.1; done
+             touch /tmp/barrier2
+             until [ -f /tmp/barrier3 ]; do sleep 0.1; done",
+        ])
+        .output(&env)
+        .assert_success();
+}
+
+#[test]
+fn stdin_pipe() {
+    let env = Env([SUDOERS_ALL_ALL_NOPASSWD, "Defaults use_pty"]).build();
+
+    // Everything is put in a single command with separators to keep the pts numbers predictable
+    Command::new("sh")
+        .args([
+            "-c",
+            "ls -l /proc/self/fd > /tmp/output; echo @@@@ >> /tmp/output; sudo -b sh -c 'ls -l /proc/self/fd; touch /tmp/barrier' >> /tmp/output",
+        ])
+        .tty(true)
+        .output(&env)
+        .assert_success();
+
+    let stdout = Command::new("sh")
+        .args([
+            "-c",
+            "until [ -f /tmp/barrier ]; do sleep 0.1; done; cat /tmp/output",
+        ])
+        .output(&env)
+        .stdout();
+
+    dbg!(&stdout);
+
+    let (term_in, term_background) = stdout.split_once("@@@@").unwrap();
+    assert_contains!(term_in, " 0 -> /dev/pts/0");
+    assert_contains!(term_in, " 1 -> /tmp/output");
+    assert_contains!(term_in, " 2 -> /dev/pts/0");
+    // Background mode makes stdin a half-open pipe and handles stdout and stderr like normal.
+    assert_contains!(term_background, " 0 -> pipe:");
+    assert_contains!(term_background, " 1 -> /tmp/output");
+    assert_contains!(term_background, " 2 -> /dev/pts/0");
+}