int-sftp outbound-gateway command-options is being ignored - spring-integration

Question

I'm trying to get a list of filenames from a remote directory and all its subdirectories using Spring Integration 4.1.5. Since I can only use SFTP to connect to the remote server, I need to use an int-sftp:outbound-gateway. Seems like it would be pretty straightforward:
<int-sftp:outbound-gateway id="remoteSftpLS"
session-factory="sftpSessionFactory"
request-channel="triggerChannel"
command="ls"
command-options="-1 -R"
remote-file-separator="/"
expression="payload"
charset="UTF-8"
filter="fileFilter"
reply-channel="lsResultChannel" />
However, it seems like anything I put into command-options is ignored:
Regardless of whether I use -R or not, I only get entries from the
top-level directory.
Regardless of whether I use -1 or not, I only get FileInfo objects, not filename strings.
What am I missing here?

Answer 1

Does not make sense. Just have tested it locally. The result is like:
payload = {ArrayList#3873} size = 3
0 = "sftpSource1.txt"
1 = "sftpSource2.txt"
2 = "subSftpSource/subSftpSource1.txt"
SftpServerOutboundTests.testInt3172LocalDirectoryExpressionMGETRecursive with the sftpSource as a remote directory and:
<int-sftp:outbound-gateway session-factory="sftpSessionFactory"
request-channel="inboundMGetRecursive"
command="ls"
expression="payload"
command-options="-1 -R"
reply-channel="output"/>
as a config.
Maybe your filter is guilty ?
protected final List<F> filterFiles(F[] files) {
return (this.filter != null) ? this.filter.filterFiles(files) : Arrays.asList(files);
}