UpdateFilter.do returns incorrect "Filter name in use" error

Incorrect error message is returned when calling the UpdateFilter.do API to update settings of an existing backup filter.

"Filter name is already in use" is always returned with status error, which is incorrect. For example:

API call: UpdateFilter.do

JSON Post:
{
"SysUser":"system",
"SysPwd":"system",
"LoginName":"username",
"BackupSetID":"backupset_id",
"Name":"filter_name",
"ID":"filter_id",
"TopDir":"C:\\directory",
"Type":"DEFAULT",
"Include":false,
"Only":true,
"Apply2Dir":true,
"Apply2File":true,
"Patterns":[{"Pattern":".txt"},{"Pattern":".png"}]
}

JSON Return:
{
"Status":"Error",
"Message":"Filter name is already in use.",
"ExptType":"com.ahsay.obs.core.dbs.e"
}