errcheck: More error handling

internal/backend/rclone/backend.go

@@ -63,9 +63,9 @@ func run(command string, args ...string) (*StdioConn, *exec.Cmd, *sync.WaitGroup
 
 	stdout, w, err := os.Pipe()
 	if err != nil {
-		// close first pipe
+		// close first pipe and ignore subsequent errors
-		r.Close()
+		_ = r.Close()
-		stdin.Close()
+		_ = stdin.Close()
 		return nil, nil, nil, nil, err
 	}
 
@@ -197,8 +197,8 @@ func newBackend(cfg Config, lim limiter.Limiter) (*Backend, error) {
 		err := cmd.Wait()
 		debug.Log("Wait returned %v", err)
 		be.waitResult = err
-		// close our side of the pipes to rclone
+		// close our side of the pipes to rclone, ignore errors
-		stdioConn.CloseAll()
+		_ = stdioConn.CloseAll()
 		close(waitCh)
 	}()
 
@@ -237,13 +237,17 @@ func newBackend(cfg Config, lim limiter.Limiter) (*Backend, error) {
 
 	res, err := ctxhttp.Do(ctx, client, req)
 	if err != nil {
-		bg()
+		// ignore subsequent errors
+		_ = bg()
 		_ = cmd.Process.Kill()
 		return nil, errors.Errorf("error talking HTTP to rclone: %v", err)
 	}
 
 	debug.Log("HTTP status %q returned, moving instance to background", res.Status)
-	bg()
+	err = bg()
+	if err != nil {
+		return nil, fmt.Errorf("error moving process to background: %w", err)
+	}
 
 	return be, nil
 }

internal/backend/rclone/internal_test.go

@@ -23,7 +23,9 @@ func TestRcloneExit(t *testing.T) {
 		return
 	}
 	rtest.OK(t, err)
-	defer be.Close()
+	defer func() {
+		rtest.OK(t, be.Close())
+	}()
 
 	err = be.cmd.Process.Kill()
 	rtest.OK(t, err)

internal/checker/checker.go

@@ -327,7 +327,12 @@ func (c *Checker) Structure(ctx context.Context, p *progress.Counter, errChan ch
 		})
 	}
 
-	wg.Wait()
+	// the wait group should not return an error because no worker returns an
+	// error, so panic if that has changed somehow.
+	err := wg.Wait()
+	if err != nil {
+		panic(err)
+	}
 }
 
 func (c *Checker) checkTree(id restic.ID, tree *restic.Tree) (errs []error) {

internal/ui/json/backup.go

@@ -79,7 +79,10 @@ func NewBackup(term *termstatus.Terminal, verbosity uint) *Backup {
 
 func toJSONString(status interface{}) string {
 	buf := new(bytes.Buffer)
-	json.NewEncoder(buf).Encode(status)
+	err := json.NewEncoder(buf).Encode(status)
+	if err != nil {
+		panic(err)
+	}
 	return buf.String()
 }
 

internal/walker/walker_test.go

@@ -28,17 +28,23 @@ func buildTreeMap(tree TestTree, m TreeMap) restic.ID {
 	for name, item := range tree {
 		switch elem := item.(type) {
 		case TestFile:
-			res.Insert(&restic.Node{
+			err := res.Insert(&restic.Node{
 				Name: name,
 				Type: "file",
 			})
+			if err != nil {
+				panic(err)
+			}
 		case TestTree:
 			id := buildTreeMap(elem, m)
-			res.Insert(&restic.Node{
+			err := res.Insert(&restic.Node{
 				Name:    name,
 				Subtree: &id,
 				Type:    "dir",
 			})
+			if err != nil {
+				panic(err)
+			}
 		default:
 			panic(fmt.Sprintf("invalid type %T", elem))
 		}