Fix remote client rejecting empty --detach-keys string

The remote client (podman --remote) was incorrectly throwing an error
when --detach-keys="" was specified for attach, run, or start commands.
According to documentation and the v1.7.0 release notes, specifying an
empty string should disable detaching, not cause an error.

Fixes: #27414

Signed-off-by: shiavm006 <[email protected]>

Author: shiavm006

pkg/bindings/containers/attach.go

@@ -80,9 +80,14 @@ func Attach(ctx context.Context, nameOrID string, stdin io.Reader, stdout io.Wri
 	if options.Changed("DetachKeys") {
 		params.Add("detachKeys", options.GetDetachKeys())
 
-		detachKeysInBytes, err = term.ToBytes(options.GetDetachKeys())
-		if err != nil {
-			return fmt.Errorf("invalid detach keys: %w", err)
+		// Empty string disables detaching; do not attempt to parse
+		if options.GetDetachKeys() == "" {
+			detachKeysInBytes = []byte{}
+		} else {
+			detachKeysInBytes, err = term.ToBytes(options.GetDetachKeys())
+			if err != nil {
+				return fmt.Errorf("invalid detach keys: %w", err)
+			}
 		}
 	}
 	if isSet.stdin {

test/system/030-run.bats

@@ -1226,6 +1226,14 @@ EOF
     run_podman rm $ctr_name
 }
 
+# Regression test for https://github.com/containers/podman/issues/27414
+# bats test_tags=ci:parallel
+@test "podman run with empty --detach-keys" {
+    # Empty string should disable detaching, not error with "invalid detach keys"
+    run_podman run --rm --detach-keys="" $IMAGE echo "success"
+    is "$output" "success" "empty detach-keys should work"
+}
+
 # 15895: --privileged + --systemd = hide /dev/ttyNN
 # bats test_tags=ci:parallel
 @test "podman run --privileged as root with systemd will not mount /dev/tty" {