lupdate orders messages differently depending on "-locations" argument

(Regarding affects version: since a long time)

Running "lupdate -locations none -no-ui-lines -no-obsolete" versus "-locations relative -no-ui-lines" can order indidvidual messages differently. For example when running these on qt-creator/qt-creator.git commit 36bcd0876b7a26cc0030966ad2cf8a523c58f395 (just before QtC 16 lupdate), I get a diff that contains for example

<context>
     <name>QtC::AppManager</name>
     <message>
......
         <source>Using: %1.</source>
         <translation>Verwende: %1.</translation>
     </message>
     <message>
+        <location line="+31"/>
+        <source>Cannot debug: Invalid target information.</source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message>
+        <location line="+17"/>
         <source>Cannot debug: Only QML and native applications are supported.</source>
......
         <source>Packager:</source>
         <translation>Packager:</translation>
     </message>
-    <message>
-        <source>Cannot debug: Invalid target information.</source>
-        <translation type="unfinished"></translation>
-    </message>
 </context>

so the "-locations none" call has the "Cannot debug" message further down than the "-locations relative" call. The latter probably has the message further up, because then it can "reuse" the "<location filename="../../../src/plugins/qtapplicationmanager/appmanagerruncontrol.cpp"" from an earlier message, which avoids repeating file paths over and over again. And it looks like "-locations none" does not follow the same logic there.