feat: compatibility with Go 1.20

Signed-off-by: juan131 <jariza@vmware.com>

cmd/csaf_downloader/forwarder.go

@@ -57,13 +57,25 @@ type forwarder struct {
 
 // newForwarder creates a new forwarder.
 func newForwarder(cfg *config) *forwarder {
-	queue := max(1, cfg.ForwardQueue)
+	queue := maxIntSlice(1, cfg.ForwardQueue)
 	return &forwarder{
 		cfg:  cfg,
 		cmds: make(chan func(*forwarder), queue),
 	}
 }
 
+// maxIntSlice returns the maximum value of a slice of integers.
+// TODO: replace with max built-in function in Go 1.21 (https://pkg.go.dev/builtin#max)
+func maxIntSlice(v1 int, vn ...int) (m int) {
+	m = v1
+	for _, x := range vn {
+		if x > m {
+			m = x
+		}
+	}
+	return
+}
+
 // run runs the forwarder. Meant to be used in a Go routine.
 func (f *forwarder) run() {
 	defer slog.Debug("forwarder done")

examples/purls_searcher/main.go

@@ -70,7 +70,10 @@ func newURLFinder(ids []string) *urlFinder {
 
 // clear resets the url finder after a run on an advisory.
 func (uf *urlFinder) clear() {
-	clear(uf.urls)
+	// TODO: replace with clear built-in function in Go 1.21 (https://pkg.go.dev/builtin#clear)
+	for i := range uf.urls {
+		uf.urls[i] = uf.urls[i][:0]
+	}
 }
 
 // dumpURLs dumps the found URLs to stdout.

go.mod

@@ -1,6 +1,6 @@
 module github.com/csaf-poc/csaf_distribution/v3
 
-go 1.21
+go 1.20
 
 require (
 	github.com/BurntSushi/toml v1.3.2