Fix config corruption bug caused by parallel writes to the same tmp file to fix #47

client/client_test.go

@@ -12,6 +12,7 @@ import (
 	"runtime"
 	"strconv"
 	"strings"
+	"sync"
 	"testing"
 	"time"
 
@@ -2290,6 +2291,43 @@ echo foo`)
 	compareGoldens(t, out, "testRemoveDuplicateRows-enabled-tquery")
 }
 
+func TestSetConfigNoCorruption(t *testing.T) {
+	// Setup
+	tester := zshTester{}
+	defer testutils.BackupAndRestore(t)()
+	installHishtory(t, tester, "")
+
+	// A test that tries writing a config many different times in parallel, and confirms there is no corruption
+	conf, err := hctx.GetConfig()
+	testutils.Check(t, err)
+	var doneWg sync.WaitGroup
+	for i := 0; i < 10; i++ {
+		doneWg.Add(1)
+		go func(i int) {
+			// Make a new config of a varied length
+			c := conf
+			c.LastSavedHistoryLine = strings.Repeat("A", i)
+			c.DeviceId = strings.Repeat("B", i*2)
+			c.HaveMissedUploads = (i % 2) == 0
+			// Write it
+			err := hctx.SetConfig(c)
+			if err != nil {
+				panic(err)
+			}
+			// Check that we can read
+			c2, err := hctx.GetConfig()
+			if err != nil {
+				panic(err)
+			}
+			if c2.UserSecret != c.UserSecret {
+				panic("user secret mismatch")
+			}
+			doneWg.Done()
+		}(i)
+	}
+	doneWg.Wait()
+}
+
 type deviceSet struct {
 	deviceMap     *map[device]deviceOp
 	currentDevice *device

client/hctx/hctx.go

@@ -11,6 +11,7 @@ import (
 	"time"
 
 	"github.com/ddworken/hishtory/client/data"
+	"github.com/google/uuid"
 	"github.com/sirupsen/logrus"
 	"gopkg.in/natefinch/lumberjack.v2"
 	"gorm.io/gorm"
@@ -237,7 +238,7 @@ func SetConfig(config ClientConfig) error {
 		return err
 	}
 	configPath := path.Join(homedir, data.HISHTORY_PATH, data.CONFIG_PATH)
-	stagedConfigPath := configPath + ".tmp"
+	stagedConfigPath := configPath + ".tmp-" + uuid.Must(uuid.NewRandom()).String()
 	err = os.WriteFile(stagedConfigPath, serializedConfig, 0o644)
 	if err != nil {
 		return fmt.Errorf("failed to write config: %v", err)