Answer
The Jar is reduced in size! The directory entries are removed, because they are never used. In every entry is normally written a size of -1, so the real size comes after the entry. Now the entry has the correct size. It saves 2nd size entry.Answer
The jlink is called for the module in the jar. If it is an automatic module the module-info is generated and added to the jar. Warning the rules for dependencies of modules are more strict than to jars. So you had to correct the dependencies if there is an error in the call to jlink.