[BUG] Error in assertion checking of assert-string-value for fn:round

[alanpaxton]

Describe the bug

K2-RoundFunc-54	Failure	assert-string-value: expected=' -0', actual='-0'

<test-case name="K2-RoundFunc-54">
      <description> Invoke on -0.14, type xs:double. </description>
      <created by="Frans Englich" on="2007-11-26"/>
      <test>fn:round(xs:double("-0.14"))</test>
      <result>
         <all-of>
            <assert-type>xs:double</assert-type>
            <assert-string-value>-0</assert-string-value>
         </all-of>
      </result>
   </test-case>

Expected behavior I expect this test to pass. I believe the interpretation of the <result> is not completely accurate.

To Reproduce This test relies on an implementation of fn:round which is currently part of a pull request https://github.com/eXist-db/exist/pull/4400. It should be deferred until the PR has been merged. Then, sbt "run --test-set fn-round"

Context (please always complete the following information):

• OS: [e.g. macOS 11.6.5
• eXist-db Version: 6.1.0-SNAPSHOT
• Java Version: OpenJDK Runtime Environment Corretto-15.0.1.9.1 (build 15.0.1+9)
  • App Version: 1.0.0

Additional context

• How is eXist-db installed? built from source