Merge remote-tracking branch 'origin/master' into fix-1063

Cargo.lock

@@ -99,6 +99,7 @@ dependencies = [
  "assert_cmd",
  "atty",
  "clap",
+ "clircle",
  "console",
  "content_inspector",
  "dirs",
@@ -117,6 +118,7 @@ dependencies = [
  "syntect",
  "tempdir",
  "unicode-width",
+ "wait-timeout",
  "wild",
 ]
 
@@ -251,6 +253,18 @@ dependencies = [
  "vec_map",
 ]
 
+[[package]]
+name = "clircle"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e27a01e782190a8314e65cc94274d9bbcd52e05a9d15b437fe2b31259b854b0d"
+dependencies = [
+ "cfg-if 1.0.0",
+ "nix",
+ "serde",
+ "winapi",
+]
+
 [[package]]
 name = "console"
 version = "0.14.0"
@@ -691,6 +705,18 @@ dependencies = [
  "autocfg",
 ]
 
+[[package]]
+name = "nix"
+version = "0.19.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b2ccba0cfe4fdf15982d1674c69b1fd80bad427d293849982668dfe454bd61f2"
+dependencies = [
+ "bitflags",
+ "cc",
+ "cfg-if 1.0.0",
+ "libc",
+]
+
 [[package]]
 name = "normalize-line-endings"
 version = "0.3.0"

Cargo.toml

@@ -50,6 +50,7 @@ serde = { version = "1.0", features = ["derive"] }
 serde_yaml = "0.8"
 semver = "0.11"
 path_abs = { version = "0.5", default-features = false }
+clircle = "0.2.0"
 
 [dependencies.git2]
 version = "0.13"
@@ -76,6 +77,7 @@ tempdir = "0.3"
 assert_cmd = "1.0.2"
 serial_test = "0.5.1"
 predicates = "1.0.6"
+wait-timeout = "0.2.0"
 
 [build-dependencies]
 clap = { version = "2.33", optional = true }

src/controller.rs

@@ -1,3 +1,4 @@
+use std::convert::TryFrom;
 use std::io::{self, Write};
 
 use crate::assets::HighlightingAssets;
@@ -66,6 +67,14 @@ impl<'b> Controller<'b> {
         }
 
         let attached_to_pager = output_type.is_pager();
+        let rw_cycle_detected = !attached_to_pager && {
+            let identifiers: Vec<_> = inputs
+                .iter()
+                .flat_map(clircle::Identifier::try_from)
+                .collect();
+            clircle::stdout_among_inputs(&identifiers)
+        };
+
         let writer = output_type.handle()?;
         let mut no_errors: bool = true;
 
@@ -78,6 +87,11 @@ impl<'b> Controller<'b> {
             }
         };
 
+        if rw_cycle_detected {
+            print_error(&"The output file is also an input!".into(), writer);
+            return Ok(false);
+        }
+
         for (index, input) in inputs.into_iter().enumerate() {
             match input.open(io::stdin().lock()) {
                 Err(error) => {

src/input.rs

@@ -1,6 +1,8 @@
+use std::convert::TryFrom;
 use std::ffi::{OsStr, OsString};
 use std::fs::File;
 use std::io::{self, BufRead, BufReader, Read};
+use std::path::Path;
 
 use content_inspector::{self, ContentType};
 
@@ -191,6 +193,18 @@ impl<'a> Input<'a> {
     }
 }
 
+impl TryFrom<&'_ Input<'_>> for clircle::Identifier {
+    type Error = ();
+
+    fn try_from(input: &Input) -> std::result::Result<clircle::Identifier, ()> {
+        match input.kind {
+            InputKind::OrdinaryFile(ref path) => Self::try_from(Path::new(path)).map_err(|_| ()),
+            InputKind::StdIn => Self::try_from(clircle::Stdio::Stdin).map_err(|_| ()),
+            InputKind::CustomReader(_) => Err(()),
+        }
+    }
+}
+
 pub(crate) struct InputReader<'a> {
     inner: Box<dyn BufRead + 'a>,
     pub(crate) first_line: Vec<u8>,

tests/integration_tests.rs

@@ -1,13 +1,19 @@
-use assert_cmd::Command;
+use assert_cmd::assert::OutputAssertExt;
+use assert_cmd::cargo::CommandCargoExt;
 use predicates::{prelude::predicate, str::PredicateStrExt};
 use serial_test::serial;
 use std::env;
+use std::fs::File;
 use std::path::{Path, PathBuf};
+use std::process::{Command, Stdio};
 use std::str::from_utf8;
+use std::time::Duration;
 
 const EXAMPLES_DIR: &str = "tests/examples";
+const SAFE_CHILD_PROCESS_CREATION_TIME: Duration = Duration::from_millis(100);
+const CHILD_WAIT_TIMEOUT: Duration = Duration::from_secs(15);
 
-fn bat_with_config() -> Command {
+fn bat_raw_command() -> Command {
     let mut cmd = Command::cargo_bin("bat").unwrap();
     cmd.current_dir("tests/examples");
     cmd.env_remove("PAGER");
@@ -19,7 +25,11 @@ fn bat_with_config() -> Command {
     cmd
 }
 
-fn bat() -> Command {
+fn bat_with_config() -> assert_cmd::Command {
+    assert_cmd::Command::from_std(bat_raw_command())
+}
+
+fn bat() -> assert_cmd::Command {
     let mut cmd = bat_with_config();
     cmd.arg("--no-config");
     cmd
@@ -258,6 +268,80 @@ fn line_range_multiple() {
         .stdout("line 1\nline 2\nline 4\n");
 }
 
+#[test]
+fn basic_io_cycle() {
+    let file_out = Stdio::from(File::open("tests/examples/cycle.txt").unwrap());
+    bat_raw_command()
+        .arg("test.txt")
+        .arg("cycle.txt")
+        .stdout(file_out)
+        .assert()
+        .failure();
+}
+
+#[test]
+fn stdin_to_stdout_cycle() {
+    let file_out = Stdio::from(File::open("tests/examples/cycle.txt").unwrap());
+    let file_in = Stdio::from(File::open("tests/examples/cycle.txt").unwrap());
+    bat_raw_command()
+        .stdin(file_in)
+        .arg("test.txt")
+        .arg("-")
+        .stdout(file_out)
+        .assert()
+        .failure();
+}
+
+#[cfg(unix)]
+#[test]
+fn no_args_doesnt_break() {
+    use std::io::Write;
+    use std::os::unix::io::FromRawFd;
+    use std::thread;
+
+    use clircle::nix::pty::{openpty, OpenptyResult};
+    use wait_timeout::ChildExt;
+
+    // To simulate bat getting started from the shell, a process is created with stdin and stdout
+    // as the slave end of a pseudo terminal. Although both point to the same "file", bat should
+    // not exit, because in this case it is safe to read and write to the same fd, which is why
+    // this test exists.
+    let OpenptyResult { master, slave } = openpty(None, None).expect("Couldn't open pty.");
+    let mut master = unsafe { File::from_raw_fd(master) };
+    let stdin = unsafe { Stdio::from_raw_fd(slave) };
+    let stdout = unsafe { Stdio::from_raw_fd(slave) };
+
+    let mut child = bat_raw_command()
+        .stdin(stdin)
+        .stdout(stdout)
+        .spawn()
+        .expect("Failed to start.");
+
+    // Some time for the child process to start and to make sure, that we can poll the exit status.
+    // Although this waiting period is not necessary, it is best to keep it in and be absolutely
+    // sure, that the try_wait does not error later.
+    thread::sleep(SAFE_CHILD_PROCESS_CREATION_TIME);
+
+    // The child process should be running and waiting for input,
+    // therefore no exit status should be available.
+    let exit_status = child
+        .try_wait()
+        .expect("Error polling exit status, this should never happen.");
+    assert!(exit_status.is_none());
+
+    // Write Ctrl-D (end of transmission) to the pty.
+    master
+        .write_all(&[0x04])
+        .expect("Couldn't write EOT character to master end.");
+
+    let exit_status = child
+        .wait_timeout(CHILD_WAIT_TIMEOUT)
+        .expect("Error polling exit status, this should never happen.")
+        .expect("Exit status not set, but the child should have exited already.");
+
+    assert!(exit_status.success());
+}
+
 #[test]
 fn tabs_numbers() {
     bat()