Rest api doesn't work when page title starts with a number

Summary

Rest api call doesn't work correctly when the page title starts with numbers

Environment

Confluence 5.10.8

Steps to Reproduce

1. Create a page and name it "test"
2. Run this call:

    curl -u admin:admin -s -n http://localhost:8090/rest/api/content/search?cql=title=test | python -mjson.tool

3. Call returns correct result
4. Now create a page and call 100test
5. Run this call:

    curl -u admin:admin -s -n http://localhost:8090/rest/api/content/search?cql=title=100test | python -mjson.tool

Expected Results

You should get a result of the search since the page exist.

Actual Results

You get a 400 error like the following

{
    "data": {
        "authorized": false,
        "errors": [],
        "notSuccessful": true,
        "successful": false,
        "valid": true
    },
    "message": "Unrecognised clause at : test",
    "statusCode": 400
}

Workaround

Encode the " when running the query to look like this

curl -u admin:admin -s -n http://localhost:8090/rest/api/content/search?cql=title=%22100test%22 | python -mjson.tool