The documentation for the "property" task contains the following line: http://ant.apache.org/manual/Tasks/property.html: "Since Apache Ant 1.7.1 it is possible to load properties defined in xml according to Suns DTD, if Java5+ is present. For this the name of the file, resource or url has to end with .xml" a) This doesn't seem to be true for 1.7.1 and I could find no indication in the Property.java source that this was the case. b) 1.8.1+ versions of Property.java do contain the functionality described above (see the loadProperties method) but their Javadoc is marked @since 1.7.1 It's possible that I have misunderstood your usage of "since" (in which case: apologies), but it has been my understanding that it means that the functionality was present "in that version", not "after that version". Either way, it's either a mistake or misleading.
The functionality has been added for bug 42946 in svn revision 559386 - by that time we had created a branch for 1.7.1 and the patch didn't get merged into the branch. The since-tags have been added later and were attributed to 1.7.1 by accident because the patch was added before the release. Fixed in svn revision 1330090