Better error handling, many fixes all around

gemini/gemini_url.go

@@ -3,8 +3,11 @@ package gemini
 import (
 	"database/sql/driver"
 	"fmt"
+	"gemini-grc/logging"
 	"net/url"
+	"path"
 	"strconv"
+	"strings"
 )
 
 type URL struct {
@@ -38,7 +41,13 @@ func (u URL) String() string {
 	return u.Full
 }
 
-// Value implements the driver.Valuer interface
+func (u URL) StringNoDefaultPort() string {
+	if u.Port == 1965 {
+		return fmt.Sprintf("%s://%s%s", u.Protocol, u.Hostname, u.Path)
+	}
+	return u.Full
+}
+
 func (u URL) Value() (driver.Value, error) {
 	if u.Full == "" {
 		return nil, nil
@@ -65,3 +74,24 @@ func ParseURL(input string, descr string) (*URL, error) {
 	full := fmt.Sprintf("%s://%s:%d%s", protocol, hostname, port, path)
 	return &URL{Protocol: protocol, Hostname: hostname, Port: port, Path: path, Descr: descr, Full: full}, nil
 }
+
+func DeriveAbsoluteURL(currentURL URL, input string) (*URL, error) {
+	logging.LogDebug("Calculating redirect URL. Current %s header string %s", currentURL, input)
+	// If URL is absolute, return just it
+	if strings.Contains(input, "://") {
+		return ParseURL(input, "")
+	}
+	// input is a path. Clean it and construct
+	// new path
+	var newPath string
+	// Handle weird cases found in the wild
+	if strings.HasPrefix(input, "/") {
+		newPath = path.Clean(input)
+	} else if input == "./" || input == "." {
+		newPath = path.Join(currentURL.Path, "/")
+	} else {
+		newPath = path.Join(currentURL.Path, path.Clean(input))
+	}
+	strURL := fmt.Sprintf("%s://%s:%d%s", currentURL.Protocol, currentURL.Hostname, currentURL.Port, newPath)
+	return ParseURL(strURL, "")
+}