[binary.jvm] ZipException raised with zip that have different entries with the same name

[lgirault]

The task binary.jvm calls the cli org.pantsbuild.tools.jar.Main. If the target of the task has a jar dependency that contains different entries with the same name (e.g: http://central.maven.org/maven2/org/seleniumhq/selenium/htmlunit-driver/2.27/htmlunit-driver-2.27.jar ) the cli will raise an exception : Unexpected problem writing target jar target.jar: java.util.zip.ZipException: invalid entry size (expected x but got y bytes)

To reproduce use the following BUILD

jar_library(name='htmlunit-driver',
  jars=[
    jar(org='org.seleniumhq.selenium',
    name='htmlunit-driver',
    rev='2.27'),
  ],
)
jvm_binary(
    name='bug',
    dependencies=[':htmlunit-driver']
    )

and assuming the file is bug/BUILD type ./pants binary.jvm bug.

To find out the exact problem I used the following utils :
unizip -t htmlunit-driver-2.27.jar -> you can see duplicated entry
zip -d htmlunit-driver-2.27.jar "org/*" -> remove non problematic file to make next comand output more readable
zipdetails htmlunit-driver-2.27.jar you can see that pom.properties do not have the same CRC (pom.xml is also duplicated but they are identical and this does not make the cli to crash)