fix: terminal hangs, right arrow blocking, and runaway iris processes (#142)

closes #137

- right arrow consumed the escape sequence without forwarding it, so the
cursor couldn't move back right after moving left (60149a2)
- p10k's instant prompt redirects stdout to a temp file that exec iris
inherits, sending the overlay there instead of the terminal and looking
like a dead keyboard. Reopens /dev/tty when stdout isn't a terminal
(7ebbb0c)
- zsh/bash autostart lacked the interactivity check fish already had, so
agentic tools sourcing your rc file spawned a rogue iris that seized
/dev/tty (5fe58be)

root/init.go

@@ -31,7 +31,9 @@ if [ -n "$IRIS_PID" ] && [ "$IRIS_PID" != "$PPID" ] && [ "${TTY:-$(tty 2>/dev/nu
     unset IRIS_PID IRIS_IS_CHILD IRIS_FD IRIS_TTY
 fi
 
-if [ -z "$IRIS_PID" ] && [ -z "$IRIS_RESCUE" ]; then
+# a non-interactive shell (tool runners sourcing rc files, scripts) has no
+# prompt to complete, and exec'ing here would seize the tty from the real iris
+if [[ -o interactive ]] && [ -t 0 ] && [ -z "$IRIS_PID" ] && [ -z "$IRIS_RESCUE" ]; then
     export IRIS_ACTIVE_SHELL="zsh"
     exec iris
 fi
@@ -74,7 +76,9 @@ if [ -n "$IRIS_PID" ] && [ "$IRIS_PID" != "$PPID" ] && [ "$(tty 2>/dev/null)" !=
     unset IRIS_PID IRIS_IS_CHILD IRIS_FD IRIS_TTY
 fi
 
-if [ -z "$IRIS_PID" ] && [ -z "$IRIS_RESCUE" ]; then
+# a non-interactive shell (tool runners sourcing rc files, scripts) has no
+# prompt to complete, and exec'ing here would seize the tty from the real iris
+if [[ $- == *i* ]] && [ -t 0 ] && [ -z "$IRIS_PID" ] && [ -z "$IRIS_RESCUE" ]; then
     export IRIS_ACTIVE_SHELL="bash"
     exec iris
 fi

root/init_test.go

@@ -0,0 +1,59 @@
+package root
+
+import (
+	"io"
+	"os"
+	"strings"
+	"testing"
+)
+
+func captureInitScript(t *testing.T, shell string) string {
+	t.Helper()
+
+	r, w, err := os.Pipe()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	original := os.Stdout
+	os.Stdout = w
+	initCmd.Run(initCmd, []string{shell})
+	_ = w.Close()
+	os.Stdout = original
+
+	out, err := io.ReadAll(r)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return string(out)
+}
+
+// a tool runner that sources the rc file in a non-interactive shell must not
+// exec a second iris, which would seize the tty from the one already running
+func TestInitAutostartRequiresInteractiveShell(t *testing.T) {
+	guards := map[string]string{
+		"zsh":  "[[ -o interactive ]]",
+		"bash": "[[ $- == *i* ]]",
+		"fish": "status is-interactive",
+	}
+
+	for shell, guard := range guards {
+		t.Run(shell, func(t *testing.T) {
+			script := captureInitScript(t, shell)
+
+			head, _, found := strings.Cut(script, "exec iris")
+			if !found {
+				t.Fatalf("%s init script has no autostart", shell)
+			}
+
+			cond := strings.LastIndex(head, "\nif ")
+			if cond < 0 {
+				t.Fatalf("%s autostart is not inside an if", shell)
+			}
+
+			if !strings.Contains(head[cond:], guard) {
+				t.Fatalf("%s autostart is not guarded by %q:\n%s", shell, guard, head[cond:])
+			}
+		})
+	}
+}

root/wrapper.go

@@ -107,6 +107,17 @@ func writeStdout(data []byte) {
 	_, _ = os.Stdout.Write(data)
 }
 
+func restoreStdoutTTY() {
+	if term.IsTerminal(int(os.Stdout.Fd())) {
+		return
+	}
+	tty, err := os.OpenFile("/dev/tty", os.O_WRONLY, 0)
+	if err != nil {
+		return
+	}
+	os.Stdout = tty
+}
+
 // restoreTerminal restores the terminal state if needed
 func restoreTerminal() {
 	oldStateMu.Lock()
@@ -129,6 +140,8 @@ func syncProcessCWD(cwd string) {
 // it handles raw terminal mode to intercept keystrokes and
 // coordinates between the shell process and the suggestion overlay
 func runWrapper() {
+	restoreStdoutTTY()
+
 	var naiveBuffer string
 	var lastSubmittedCommand string
 	cursorOffset := 0
@@ -1057,6 +1070,7 @@ func runWrapper() {
 								}
 								continue
 							}
+							rawSeq := append([]byte(nil), inputSlice[i:i+navConsumed]...)
 							i += navConsumed - 1
 							intercepted = true
 							bufferMu.Lock()
@@ -1095,6 +1109,7 @@ func runWrapper() {
 								userNavigated.Store(false)
 							}
 							bufferMu.Unlock()
+							_, _ = ptmx.Write(rawSeq)
 							isLeftRightArrow = true
 						}
 					}

root/wrapper_test.go

@@ -4,6 +4,8 @@ import (
 	"os"
 	"path/filepath"
 	"testing"
+
+	"golang.org/x/term"
 )
 
 func wantDir(t *testing.T, path string) string {
@@ -24,6 +26,55 @@ func currentDir(t *testing.T) string {
 	return wantDir(t, cwd)
 }
 
+func TestRestoreStdoutTTYRedirectsFileStdoutToTerminal(t *testing.T) {
+	tty, err := os.OpenFile("/dev/tty", os.O_WRONLY, 0)
+	if err != nil {
+		t.Skip("no controlling terminal available")
+	}
+	_ = tty.Close()
+
+	// stand in for the temp file powerlevel10k's instant prompt leaves on stdout
+	redirected, err := os.CreateTemp(t.TempDir(), "instant-prompt-output")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer func() { _ = redirected.Close() }()
+
+	original := os.Stdout
+	os.Stdout = redirected
+	t.Cleanup(func() { os.Stdout = original })
+
+	restoreStdoutTTY()
+
+	if os.Stdout == redirected {
+		t.Fatal("restoreStdoutTTY left stdout pointing at the redirected file")
+	}
+	if !term.IsTerminal(int(os.Stdout.Fd())) {
+		t.Fatal("restoreStdoutTTY did not leave stdout on a terminal")
+	}
+	_ = os.Stdout.Close()
+}
+
+func TestRestoreStdoutTTYKeepsExistingTerminal(t *testing.T) {
+	tty, err := os.OpenFile("/dev/tty", os.O_WRONLY, 0)
+	if err != nil {
+		t.Skip("no controlling terminal available")
+	}
+
+	original := os.Stdout
+	os.Stdout = tty
+	t.Cleanup(func() {
+		os.Stdout = original
+		_ = tty.Close()
+	})
+
+	restoreStdoutTTY()
+
+	if os.Stdout != tty {
+		t.Fatal("restoreStdoutTTY reopened stdout that was already a terminal")
+	}
+}
+
 func TestSyncProcessCWDFollowsShell(t *testing.T) {
 	shellDir := t.TempDir()
 	t.Chdir(t.TempDir())