-DdownloadSources - sources are not in sync with binaries on SNAPSHOT versions

using the "-DdownloadSources" switch doesn't sync correctly the sources with binaries for SNAPSHOT versions.

for reproducing follow these steps:

• person A deploys an artifact with version for example 1.0-SNAPSHOT
• person B calls "mvn idea:idea -DdownloadSources -U" and the sources and the binaries of the artifact will be correctly downloaded into the local repo
• person A again deploys the changed artifact with the same version for example 1.0-SNAPSHOT
• person B again calls "mvn idea:idea -DdownloadSources -U" and the binaries will be downloaded correctly but the sources got out of sync meaning the sources from the previous call are not updated