fix: resolve RealIP for bare RemoteAddr without port (#3054)

RealIP and LegacyIPExtractor discarded the address when net.SplitHostPort
failed (e.g. bare IPv4/IPv6 without :port). Reuse extractIP so behavior
matches ExtractIPDirect.

Author: sonnemusk

context.go

@@ -12,7 +12,6 @@ import (
 	"io/fs"
 	"log/slog"
 	"mime/multipart"
-	"net"
 	"net/http"
 	"net/url"
 	"path"
@@ -252,8 +251,8 @@ func (c *Context) RealIP() string {
 	}
 	// req.RemoteAddr is the IP address of the remote end of the connection, which may be a proxy. It is populated by the
 	// http.conn.readRequest() method and uses net.Conn.RemoteAddr().String() which we trust.
-	ra, _, _ := net.SplitHostPort(c.request.RemoteAddr)
-	return ra
+	// Use extractIP so bare IPs (no host:port) still resolve, matching ExtractIPDirect.
+	return extractIP(c.request)
 }
 
 // Path returns the registered path for the handler.

context_test.go

@@ -1350,6 +1350,18 @@ func TestContext_RealIP(t *testing.T) {
 			whenReq:         &http.Request{RemoteAddr: "89.89.89.89:1654"},
 			expect:          "89.89.89.89",
 		},
+		{
+			name:            "ip from bare remote addr without port",
+			givenIPExtrator: nil,
+			whenReq:         &http.Request{RemoteAddr: "89.89.89.89"},
+			expect:          "89.89.89.89",
+		},
+		{
+			name:            "ip from bare ipv6 remote addr without port",
+			givenIPExtrator: nil,
+			whenReq:         &http.Request{RemoteAddr: "2001:db8::1"},
+			expect:          "2001:db8::1",
+		},
 		{
 			name:            "ip from ip extractor",
 			givenIPExtrator: ExtractIPFromRealIPHeader(TrustIPRange(ipv6ForRemoteAddrExternalRange)),

ip.go

@@ -304,6 +304,5 @@ func legacyIPExtractor(req *http.Request) string {
 		ip = strings.TrimSuffix(ip, "]")
 		return ip
 	}
-	ra, _, _ := net.SplitHostPort(req.RemoteAddr)
-	return ra
+	return extractIP(req)
 }