Behavior change in the jar tool JDK11 vs JDK8.

[Remi Forax]

----- Original Message -----
> From: "Pasam Soujanya1" <psoujany at in.ibm.com>
> To: "core-libs-dev" <core-libs-dev at openjdk.java.net>
> Sent: Monday, March 14, 2022 12:48:42 PM
> Subject: Behavior change in the jar tool JDK11 vs JDK8.

> There is a significant difference in the way the JAR tool (starting JDK11) seems
> to be responding to target files that are not present , when compared to JDK8.
> With JDK 8, the jar tool just reports about target files that are absent, and
> creates the jar file with whatever targets are available.
> 
> With JDK8, If I try to create a jar file with one existing file and another
> invalid file name I can see achieve getting created with the file that exists.
> Only the warning seems to be printed for the target that doesn't exists:
> 
> $ jar -cvf sample.jar exists.txt does_not_exist.txt
> does_not_exist.txt : no such file or directory
> added manifest
> adding: exists.txt(in = 0) (out= 0)(stored 0%)
> 
> From JDK11 onward upto the latest, though I can see the same verbose output the
> jar file(sample.jar) is not created.
> 
> Looking at the code, the targets that do exist are written to a temporary JAR
> file, but the following "validation" code, which runs once the tool has
> finished writing the temporary JAR file, only moves/renames the temporary file
> to the specified JAR location if "ok" is true. If "ok" is false the temporary
> file is simply deleted:
> https://github.com/openjdk/jdk11u/blob/22186cb1fe22b4b30fc72c67ce9946cd4f03199d/src/jdk.jartool/share/classes/sun/tools/jar/Main.java#L451
> 
> Is this behavior change intentional? I couldn't find anything documented in
> release notes of JDK 9,10,11. If not intentional, can someone help me create
> bug report on OpenJDK jira? Thank you.

I believe it's a bugfix, since the creation of the command "jar", jar follows the semantics of "tar", so the behavior you are seeing now is the correct one.
But i was not able to pinpoint the bug corresponding to that issue.

> 
> Regards,
> Pasam Soujanya.

regards,
Rémi