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: #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 +1,55 @@
+#!/bin/bash
+
+# test verifying syncoid behavior with partial transfers
+
+set -x
+
+. ../../common/lib.sh
+
+POOL_IMAGE="/tmp/syncoid-test-012.zpool"
+POOL_SIZE="128M"
+POOL_NAME="syncoid-test-012"
+MOUNT_TARGET="/tmp/syncoid-test-012.mount"
+
+truncate -s "${POOL_SIZE}" "${POOL_IMAGE}"
+
+zpool create -O mountpoint="${MOUNT_TARGET}" -f "${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 "${POOL_NAME}/source@empty"
+dd if=/dev/urandom of="${MOUNT_TARGET}/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"
+
+# Check if syncoid succeeded in handling the interrupted transfer
+if [ $? -eq 0 ]; then
+  echo "Syncoid resumed transfer successfully."
+
+  # Verify data integrity with sha256sum comparison
+  original_sum=$(sha256sum "${MOUNT_TARGET}/source/garbage.bin" | cut -d ' ' -f 1)
+  received_sum=$(sha256sum "${MOUNT_TARGET}/destination/garbage.bin" | cut -d ' ' -f 1)
+
+  if [ "${original_sum}" == "${received_sum}" ]; then
+    echo "Data integrity verified."
+    exit 0
+  else
+    echo "Data integrity check failed."
+    exit 1
+  fi
+else
+  echo "Regression detected: syncoid did not handle the resuming correctly."
+  exit 1
+fi