fix(deps): update module google.golang.org/grpc to v1.77.0

Signed-off-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

vendor/google.golang.org/grpc/internal/resolver/delegatingresolver/delegatingresolver.go

@@ -22,11 +22,13 @@ package delegatingresolver
 
 import (
 	"fmt"
+	"net"
 	"net/http"
 	"net/url"
 	"sync"
 
 	"google.golang.org/grpc/grpclog"
+	"google.golang.org/grpc/internal/envconfig"
 	"google.golang.org/grpc/internal/proxyattributes"
 	"google.golang.org/grpc/internal/transport"
 	"google.golang.org/grpc/internal/transport/networktype"
@@ -40,6 +42,8 @@ var (
 	HTTPSProxyFromEnvironment = http.ProxyFromEnvironment
 )
 
+const defaultPort = "443"
+
 // delegatingResolver manages both target URI and proxy address resolution by
 // delegating these tasks to separate child resolvers. Essentially, it acts as
 // an intermediary between the gRPC ClientConn and the child resolvers.
@@ -107,10 +111,18 @@ func New(target resolver.Target, cc resolver.ClientConn, opts resolver.BuildOpti
 		targetResolver: nopResolver{},
 	}
 
+	addr := target.Endpoint()
 	var err error
-	r.proxyURL, err = proxyURLForTarget(target.Endpoint())
+	if target.URL.Scheme == "dns" && !targetResolutionEnabled && envconfig.EnableDefaultPortForProxyTarget {
+		addr, err = parseTarget(addr)
+		if err != nil {
+			return nil, fmt.Errorf("delegating_resolver: invalid target address %q: %v", target.Endpoint(), err)
+		}
+	}
+
+	r.proxyURL, err = proxyURLForTarget(addr)
 	if err != nil {
-		return nil, fmt.Errorf("delegating_resolver: failed to determine proxy URL for target %s: %v", target, err)
+		return nil, fmt.Errorf("delegating_resolver: failed to determine proxy URL for target %q: %v", target, err)
 	}
 
 	// proxy is not configured or proxy address excluded using `NO_PROXY` env
@@ -132,8 +144,8 @@ func New(target resolver.Target, cc resolver.ClientConn, opts resolver.BuildOpti
 	// bypass the target resolver and store the unresolved target address.
 	if target.URL.Scheme == "dns" && !targetResolutionEnabled {
 		r.targetResolverState = &resolver.State{
-			Addresses: []resolver.Address{{Addr: target.Endpoint()}},
-			Endpoints: []resolver.Endpoint{{Addresses: []resolver.Address{{Addr: target.Endpoint()}}}},
+			Addresses: []resolver.Address{{Addr: addr}},
+			Endpoints: []resolver.Endpoint{{Addresses: []resolver.Address{{Addr: addr}}}},
 		}
 		r.updateTargetResolverState(*r.targetResolverState)
 		return r, nil
@@ -202,6 +214,44 @@ func needsProxyResolver(state *resolver.State) bool {
 	return false
 }
 
+// parseTarget takes a target string and ensures it is a valid "host:port" target.
+//
+// It does the following:
+//  1. If the target already has a port (e.g., "host:port", "[ipv6]:port"),
+//     it is returned as is.
+//  2. If the host part is empty (e.g., ":80"), it defaults to "localhost",
+//     returning "localhost:80".
+//  3. If the target is missing a port (e.g., "host", "ipv6"), the defaultPort
+//     is added.
+//
+// An error is returned for empty targets or targets with a trailing colon
+// but no port (e.g., "host:").
+func parseTarget(target string) (string, error) {
+	if target == "" {
+		return "", fmt.Errorf("missing address")
+	}
+
+	host, port, err := net.SplitHostPort(target)
+	if err != nil {
+		// If SplitHostPort fails, it's likely because the port is missing.
+		// We append the default port and return the result.
+		return net.JoinHostPort(target, defaultPort), nil
+	}
+
+	// If SplitHostPort succeeds, we check for edge cases.
+	if port == "" {
+		// A success with an empty port means the target had a trailing colon,
+		// e.g., "host:", which is an error.
+		return "", fmt.Errorf("missing port after port-separator colon")
+	}
+	if host == "" {
+		// A success with an empty host means the target was like ":80".
+		// We default the host to "localhost".
+		host = "localhost"
+	}
+	return net.JoinHostPort(host, port), nil
+}
+
 func skipProxy(address resolver.Address) bool {
 	// Avoid proxy when network is not tcp.
 	networkType, ok := networktype.Get(address)