fix(syncoid): zfs send arg allowlist when sendsource is receivetoken

The `runsynccmd` subroutine was not matching the `$sendsource` when a
receive resume token is passed in. All usages that pass in the receive
resume token do not begin with a space; instead, they start with `-t `.

Fixes: jimsalterjrs#918

syncoid

@@ -898,7 +898,7 @@ sub runsynccmd {
 
 	my $disp_pvsize = $pvsize == 0 ? 'UNKNOWN' : readablebytes($pvsize);
 	my $sendoptions;
-	if ($sendsource =~ / -t /) {
+	if ($sendsource =~ /^-t /) {
 		$sendoptions = getoptionsline(\@sendoptions, ('P','V','e','v'));
 	} elsif ($sendsource =~ /#/) {
 		$sendoptions = getoptionsline(\@sendoptions, ('L','V','c','e','w'));

tests/syncoid/012_receive_resume_token/run.sh

@@ -0,0 +1,48 @@
+#!/bin/bash
+
+# test verifying syncoid behavior with partial transfers
+
+set -x
+set -e
+
+. ../../common/lib.sh
+
+if [ -z "$ALLOW_INVASIVE_TESTS" ]; then
+  exit 130
+fi
+
+POOL_IMAGE="/tmp/jimsalterjrs_sanoid_918.img"
+POOL_SIZE="128M"
+POOL_NAME="jimsalterjrs_sanoid_918"
+
+truncate -s "${POOL_SIZE}" "${POOL_IMAGE}"
+
+zpool create -f "${POOL_NAME}" "${POOL_IMAGE}"
+
+function cleanUp {
+  zpool destroy "${POOL_NAME}"
+  rm -f "${POOL_IMAGE}"
+}
+
+# Clean up the pool and image file on exit
+trap cleanUp EXIT
+
+zfs create "${POOL_NAME}/source"
+zfs snap "${POOL_NAME}/source@empty"
+dd if=/dev/urandom of="/${POOL_NAME}/source/garbage.bin" bs=1M count=16
+zfs snap "${POOL_NAME}/source@something"
+
+# Simulate interrupted transfer
+zfs send -pwR "${POOL_NAME}/source@something" | head --bytes=8M | zfs recv -s "${POOL_NAME}/destination"
+
+# Using syncoid to continue interrupted transfer
+../../../syncoid --sendoptions="pw" "${POOL_NAME}/source" "${POOL_NAME}/destination"
+
+# Verify success based on exit status
+if [ $? -ne 0 ]; then
+  echo "Regression detected: syncoid did not handle the resuming correctly."
+  exit 1
+else
+  echo "Test passed: syncoid resumed transfer successfully."
+  exit 0
+fi