fix panic during tab-completion (#688)

Tab completion uses a nil logger with a command
where the logger was optional, but in #680,
it calls a method on the logger that it previously didn't,
which causes a panic.

This change makes two fixes:

- The function is updated to handle a nil logger like before.
- All methods of Logger are made nil-safe to prevent
  issues like this in the future

Resolves #687

Author: abhinav

.changes/v0.14.1.md

@@ -0,0 +1,3 @@
+## <a name="v0.14.1">v0.14.1</a> - 2025-05-30
+### Fixed
+- Fix panic when using shell tab completion for a branch name.

CHANGELOG.md

@@ -5,6 +5,10 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html),
 and is generated by [Changie](https://github.com/miniscruff/changie).
 
+## <a name="v0.14.1">v0.14.1</a> - 2025-05-30
+### Fixed
+- Fix panic when using shell tab completion for a branch name.
+
 ## <a name="v0.14.0">v0.14.0</a> - 2025-05-28
 ### Added
 - branch checkout: Add 'spice.branchCheckout.trackUntrackedPrompt' configuration option to disable prompting to track untracked branches upon checkout.

internal/silog/log.go

@@ -109,25 +109,35 @@ func New(w io.Writer, opts *Options) *Logger {
 // Clone returns a new logger with the same configuration
 // as the original logger.
 func (l *Logger) Clone() *Logger {
+	if l == nil {
+		return l
+	}
 	newL := *l
 	return &newL
 }
 
 // Level returns the current log level of the logger.
 func (l *Logger) Level() Level {
+	if l == nil {
+		return LevelFatal + 1
+	}
+
 	return Level(l.lvl.Level())
 }
 
 // SetLevel changes the log level of the logger
 // and all loggers cloned from it.
 func (l *Logger) SetLevel(lvl Level) {
+	if l == nil {
+		return
+	}
 	l.lvl.Set(lvl.Level())
 }
 
 // WithLevel returns a copy of this logger
 // that will log at the given level.
 func (l *Logger) WithLevel(lvl Level) *Logger {
-	if lvl == l.Level() {
+	if l == nil || lvl == l.Level() {
 		return l
 	}
 
@@ -140,6 +150,9 @@ func (l *Logger) WithLevel(lvl Level) *Logger {
 
 // WithGroup returns a copy of the logger with the given group name added.
 func (l *Logger) WithGroup(name string) *Logger {
+	if l == nil || name == "" {
+		return l
+	}
 	newL := l.Clone()
 	newL.sl = newL.sl.WithGroup(name)
 	return newL
@@ -151,6 +164,9 @@ func (l *Logger) WithGroup(name string) *Logger {
 // If the prefix is empty, an existing prefix will be removed.
 // If the prefix is non-empty, a ": " delimiter will be added.
 func (l *Logger) WithPrefix(prefix string) *Logger {
+	if l == nil {
+		return l
+	}
 	newL := l.Clone()
 	newL.sl = slog.New(newL.sl.Handler().(*logHandler).WithPrefix(prefix))
 	return newL
@@ -164,14 +180,17 @@ func (l *Logger) WithPrefix(prefix string) *Logger {
 // will be downgraded to LevelDebug,
 // Levels at the minimum level will be discarded.
 func (l *Logger) Downgrade() *Logger {
+	if l == nil {
+		return l
+	}
 	newL := l.Clone()
 	newL.numDowngrades++
 	return newL
 }
 
 // With returns a copy of the logger with the given attributes added.
 func (l *Logger) With(attrs ...any) *Logger {
-	if len(attrs) == 0 {
+	if l == nil || len(attrs) == 0 {
 		return l
 	}
 
@@ -182,6 +201,13 @@ func (l *Logger) With(attrs ...any) *Logger {
 
 // Log logs a message at the given level with the given key-value pairs.
 func (l *Logger) Log(lvl Level, msg string, kvs ...any) {
+	if l == nil {
+		if lvl >= LevelFatal {
+			_osExit(1) // exit on fatal regardless
+		}
+		return
+	}
+
 	if l.numDowngrades > 0 {
 		lvl = lvl.Dec(l.numDowngrades)
 	}
@@ -229,4 +255,6 @@ func (l *Logger) Errorf(format string, args ...any) { l.Logf(LevelError, format,
 // It also exits the program with a non-zero status code.
 func (l *Logger) Fatalf(format string, args ...any) { l.Logf(LevelFatal, format, args...) }
 
-func exitOnFatal() { os.Exit(1) }
+var _osExit = os.Exit // for testing
+
+func exitOnFatal() { _osExit(1) }

internal/silog/log_int_test.go

@@ -0,0 +1,26 @@
+package silog
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestLogger_nilSafeFatal(t *testing.T) {
+	defer func(old func(int)) {
+		_osExit = old
+	}(_osExit)
+
+	var exited bool
+	_osExit = func(int) {
+		exited = true
+	}
+
+	var logger *Logger
+	logger.Fatal("foo")
+	assert.True(t, exited)
+
+	exited = false
+	logger.Fatalf("foo %s", "bar")
+	assert.True(t, exited)
+}

internal/silog/log_test.go

@@ -375,6 +375,54 @@ func TestLogger_WithLevel(t *testing.T) {
 	assert.Empty(t, buffer.String())
 }
 
+func TestLogger_nilSafe(t *testing.T) {
+	var logger *silog.Logger
+
+	t.Run("Clone", func(*testing.T) {
+		_ = logger.Clone()
+	})
+
+	t.Run("Level", func(*testing.T) {
+		_ = logger.Level()
+	})
+
+	t.Run("SetLevel", func(*testing.T) {
+		logger.SetLevel(silog.LevelDebug)
+	})
+
+	t.Run("WithLevel", func(*testing.T) {
+		_ = logger.WithLevel(silog.LevelDebug)
+	})
+
+	t.Run("WithGroup", func(*testing.T) {
+		_ = logger.WithGroup("test")
+	})
+
+	t.Run("WithPrefix", func(*testing.T) {
+		_ = logger.WithPrefix("test")
+	})
+
+	t.Run("Downgrade", func(*testing.T) {
+		_ = logger.Downgrade()
+	})
+
+	t.Run("With", func(*testing.T) {
+		_ = logger.With("key", "value")
+	})
+
+	t.Run("Log", func(*testing.T) { logger.Log(silog.LevelInfo, "test") })
+	t.Run("Debug", func(*testing.T) { logger.Debug("test") })
+	t.Run("Info", func(*testing.T) { logger.Info("test") })
+	t.Run("Warn", func(*testing.T) { logger.Warn("test") })
+	t.Run("Error", func(*testing.T) { logger.Error("test") })
+
+	t.Run("Logf", func(*testing.T) { logger.Logf(silog.LevelInfo, "test %s", "message") })
+	t.Run("Debugf", func(*testing.T) { logger.Debugf("test %s", "message") })
+	t.Run("Infof", func(*testing.T) { logger.Infof("test %s", "message") })
+	t.Run("Warnf", func(*testing.T) { logger.Warnf("test %s", "message") })
+	t.Run("Errorf", func(*testing.T) { logger.Errorf("test %s", "message") })
+}
+
 type testStringer struct{ v string }
 
 func (s *testStringer) String() string { return s.v }

repo_init.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"cmp"
 	"context"
 	"errors"
 	"fmt"
@@ -126,6 +127,7 @@ const (
 )
 
 func newRepoStorage(repo *git.Repository, log *silog.Logger) *storage.DB {
+	log = cmp.Or(log, silog.Nop())
 	return storage.NewDB(storage.NewGitBackend(storage.GitConfig{
 		Repo:        repo.WithLogger(log.Downgrade()),
 		Ref:         _dataRef,