Fixes incorrect url for submodules that specify the remote port

  Fixes go-gitea/gitea#2775

submodule.go

@@ -4,7 +4,10 @@
 
 package git
 
-import "strings"
+import (
+    "strings"
+    "strconv"
+)
 
 // SubModule submodule is a reference on git repository
 type SubModule struct {
@@ -58,14 +61,22 @@ func (sf *SubModuleFile) RefURL(urlPrefix string, parentPath string) string {
 	}
 
 	// sysuser@xxx:user/repo
+	// or
+	// sysuser@xxx:port/user/repo
 	i := strings.Index(url, "@")
 	j := strings.LastIndex(url, ":")
 
 	// Only process when i < j because git+ssh://[email protected]/npploader.git
 	if i > -1 && j > -1 && i < j {
 		// fix problem with reverse proxy works only with local server
 		if strings.Contains(urlPrefix, url[i+1:j]) {
-			return urlPrefix + url[j+1:]
+			port := strings.Index(url[j+1:], "/")
+			_, err := strconv.ParseInt(url[j+1:j+1 + port],10,16)
+			if err != nil {
+				return urlPrefix + url[j+1:]
+			} else {
+				return urlPrefix + url[j+1 + port+1:]
+			}
 		}
 		return "http://" + url[i+1:j] + "/" + url[j+1:]
 	}