Fix various cosmetics

`staticcheck` and friends reported various smaller issues. This commit
addresses some of them.

cmd/knut/main.go

@@ -92,7 +92,7 @@ func main() {
 	flag.Usage = usage
 	flag.Parse()
 
-	if opts.doPrintVersion == true {
+	if opts.doPrintVersion {
 		fmt.Println(Version, GitHash, BuildDate)
 		os.Exit(0)
 	}

internal/pkg/knut/helper.go

@@ -17,7 +17,7 @@ var (
 	errEmptyPairParts = fmt.Errorf("empty pair parts")
 )
 
-// getWindowAndTree splits "arg" at the ':' seperator. in the context
+// getWindowAndTree splits "arg" at the ':' separator. in the context
 // of *knut* the first part is called "window" (it is the url-endpoint,
 // essentially), the part after the first ':' is called "the tree", it's
 // the content that will be delivered.

internal/pkg/knut/tar.go

@@ -75,7 +75,7 @@ func (entry *tarEntry) TarFileEventually(name string) {
 	}
 
 	tf := entry.header.Typeflag
-	if tf == tar.TypeReg || tf == tar.TypeRegA || tf == tar.TypeLink {
+	if tf == tar.TypeReg || tf == tar.TypeLink {
 		entry.TarFile(name)
 	}
 }

internal/pkg/knut/tls.go

@@ -114,7 +114,6 @@ func (ot *OnetimeTLS) fillTLSConfig() {
 		ot.tlsConfig.NextProtos = []string{"http/1.1"}
 		ot.tlsConfig.MinVersion = tls.VersionTLS11
 		ot.tlsConfig.CurvePreferences = []tls.CurveID{tls.CurveP521, tls.CurveP384, tls.CurveP256}
-		ot.tlsConfig.PreferServerCipherSuites = true
 		ot.tlsConfig.SessionTicketsDisabled = true
 		ot.tlsConfig.Certificates = make([]tls.Certificate, 1)
 		ot.tlsConfig.Certificates[0], ot.err = tls.X509KeyPair(ot.certBytes, ot.privKeyBytes)

internal/pkg/knut/upload.go

@@ -6,7 +6,6 @@ package knut
 import (
 	"fmt"
 	"io"
-	"io/ioutil"
 	"log"
 	"mime/multipart"
 	"net"
@@ -78,7 +77,7 @@ input[type="submit"] { margin-top: 1em }
 		}
 
 		fmt.Fprintln(w, htmlDoc)
-		fmt.Fprintf(w, "ok, received %d bytes over %s", nBytes, time.Now().Sub(startTime))
+		fmt.Fprintf(w, "ok, received %d bytes over %s", nBytes, time.Since(startTime))
 	})
 }
 
@@ -97,7 +96,7 @@ func storeFormFile(prefix, dir string, fh *multipart.FileHeader) (int64, error)
 	}
 	defer postedFile.Close()
 
-	osFile, err := ioutil.TempFile(dir, prefix)
+	osFile, err := os.CreateTemp(dir, prefix)
 	if err != nil {
 		return 0, err
 	}

internal/pkg/knut/zip.go

@@ -39,6 +39,11 @@ func ZipDirectory(w io.Writer, dir, prefix string, store bool) error {
 			return nil
 		}
 
+		// skip "error" entries
+		if err == nil {
+			return nil
+		}
+
 		f, err := os.Open(path)
 		if err != nil {
 			fmt.Fprintf(os.Stderr, "warning: problem open file %s for reading: %v\n",
@@ -82,10 +87,10 @@ func zipEntry(zw *zip.Writer, name string, fi os.FileInfo, store bool) (io.Write
 	}
 
 	fh.Name = name
+	fh.Method = zip.Deflate
+
 	if store {
 		fh.Method = zip.Store
-	} else {
-		fh.Method = zip.Deflate
 	}
 
 	return zw.CreateHeader(fh)

internal/pkg/knut/zipfs.go

@@ -43,7 +43,7 @@ func ZipFSHandler(name, prefix, index string) http.Handler {
 		if strings.HasSuffix(r.URL.Path, "/") {
 			if index == "" {
 				w.Header().Set("Content-Type", "text/html; charset=utf8")
-				indexFolderEntries(w, z.Reader, name)
+				indexFolderEntries(w, &z.Reader, name)
 				return
 			}
 			r.URL.Path = path.Join(r.URL.Path, index)
@@ -99,7 +99,7 @@ func serveZipEntry(w http.ResponseWriter, zFile *zip.File) {
 
 // indexFolderEntries creates an index pages page of all the file entries
 // in the given "folder"
-func indexFolderEntries(w http.ResponseWriter, zreader zip.Reader, folder string) {
+func indexFolderEntries(w http.ResponseWriter, zreader *zip.Reader, folder string) {
 
 	fmt.Fprint(w, "<pre>")
 	defer fmt.Fprint(w, "</pre>")
@@ -114,7 +114,7 @@ func indexFolderEntries(w http.ResponseWriter, zreader zip.Reader, folder string
 	}
 }
 
-func listFolderEntries(zreader zip.Reader, folder string) []string {
+func listFolderEntries(zreader *zip.Reader, folder string) []string {
 	entries := make([]string, 0)
 	for _, file := range zreader.File {