client: fix wrong usage of url.Parse (#7916)

close #7900

Signed-off-by: Cabinfever_B <[email protected]>

client/pd_service_discovery.go

@@ -1131,20 +1131,21 @@ func addrsToURLs(addrs []string, tlsCfg *tls.Config) []string {
 	return urls
 }
 
-func modifyURLScheme(uStr string, tlsCfg *tls.Config) string {
-	u, err := url.Parse(uStr)
-	if err != nil {
-		if tlsCfg != nil {
-			return httpsSchemePrefix + uStr
+func modifyURLScheme(url string, tlsCfg *tls.Config) string {
+	if tlsCfg == nil {
+		if strings.HasPrefix(url, httpsSchemePrefix) {
+			url = httpSchemePrefix + strings.TrimPrefix(url, httpsSchemePrefix)
+		} else if !strings.HasPrefix(url, httpSchemePrefix) {
+			url = httpSchemePrefix + url
 		}
-		return httpSchemePrefix + uStr
-	}
-	if tlsCfg != nil {
-		u.Scheme = httpsScheme
 	} else {
-		u.Scheme = httpScheme
+		if strings.HasPrefix(url, httpSchemePrefix) {
+			url = httpsSchemePrefix + strings.TrimPrefix(url, httpSchemePrefix)
+		} else if !strings.HasPrefix(url, httpsSchemePrefix) {
+			url = httpsSchemePrefix + url
+		}
 	}
-	return u.String()
+	return url
 }
 
 // pickMatchedURL picks the matched URL based on the TLS config.

client/pd_service_discovery_test.go

@@ -324,14 +324,44 @@ func TestServiceClientScheme(t *testing.T) {
 func TestSchemeFunction(t *testing.T) {
 	re := require.New(t)
 	tlsCfg := &tls.Config{}
+
+	endpoints1 := []string{
+		"http://tc-pd:2379",
+		"tc-pd:2379",
+		"https://tc-pd:2379",
+	}
+	endpoints2 := []string{
+		"127.0.0.1:2379",
+		"http://127.0.0.1:2379",
+		"https://127.0.0.1:2379",
+	}
+	urls := addrsToURLs(endpoints1, tlsCfg)
+	for _, u := range urls {
+		re.Equal("https://tc-pd:2379", u)
+	}
+	urls = addrsToURLs(endpoints2, tlsCfg)
+	for _, u := range urls {
+		re.Equal("https://127.0.0.1:2379", u)
+	}
+	urls = addrsToURLs(endpoints1, nil)
+	for _, u := range urls {
+		re.Equal("http://tc-pd:2379", u)
+	}
+	urls = addrsToURLs(endpoints2, nil)
+	for _, u := range urls {
+		re.Equal("http://127.0.0.1:2379", u)
+	}
+
 	re.Equal("https://127.0.0.1:2379", modifyURLScheme("https://127.0.0.1:2379", tlsCfg))
 	re.Equal("https://127.0.0.1:2379", modifyURLScheme("http://127.0.0.1:2379", tlsCfg))
 	re.Equal("https://127.0.0.1:2379", modifyURLScheme("127.0.0.1:2379", tlsCfg))
+	re.Equal("https://tc-pd:2379", modifyURLScheme("tc-pd:2379", tlsCfg))
 	re.Equal("http://127.0.0.1:2379", modifyURLScheme("https://127.0.0.1:2379", nil))
 	re.Equal("http://127.0.0.1:2379", modifyURLScheme("http://127.0.0.1:2379", nil))
 	re.Equal("http://127.0.0.1:2379", modifyURLScheme("127.0.0.1:2379", nil))
+	re.Equal("http://tc-pd:2379", modifyURLScheme("tc-pd:2379", nil))
 
-	urls := []string{
+	urls = []string{
 		"http://127.0.0.1:2379",
 		"https://127.0.0.1:2379",
 	}