ADDITIONAL SYSTEM INFORMATION :
Linux 4.15.0-55-generic #60-Ubuntu SMP Tue Jul 2 18:22:20 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux

openjdk 11.0.4 2019-07-16
OpenJDK Runtime Environment AdoptOpenJDK (build 11.0.4+11)
OpenJDK 64-Bit Server VM AdoptOpenJDK (build 11.0.4+11, mixed mode)

and

java 11.0.4 2019-07-16 LTS
Java(TM) SE Runtime Environment 18.9 (build 11.0.4+10-LTS)
Java HotSpot(TM) 64-Bit Server VM 18.9 (build 11.0.4+10-LTS, mixed mode)

A DESCRIPTION OF THE PROBLEM :
`jdeps --list-reduced-deps logback-classic-1.2.3.jar` fails with NPE in JDK 11.

In the original issue JDK-8211887 it is fixed for JDK 12, but JDK 11 is LTS hence must be fixed too.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
1. take logback-classic-1.2.3.jar from https://repo1.maven.org/maven2/ch/qos/logback/logback-classic/1.2.3/
2. Run `jdeps --list-reduced-deps logback-classic-1.2.3.jar`
   or
       `jdeps --print-module-deps logback-classic-1.2.3.jar`

exited with code 1, NPE exception is printed to STDOUT

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
no exception, exit code 0
ACTUAL -
exited with code 1, NPE exception is printed to STDOUT

Exception in thread "main" java.lang.NullPointerException
at jdk.jdeps/com.sun.tools.jdeps.ModuleGraphBuilder.requiresTransitive(ModuleGraphBuilder.java:124)
at jdk.jdeps/com.sun.tools.jdeps.ModuleGraphBuilder.buildGraph(ModuleGraphBuilder.java:110)
at jdk.jdeps/com.sun.tools.jdeps.ModuleGraphBuilder.reduced(ModuleGraphBuilder.java:65)
at jdk.jdeps/com.sun.tools.jdeps.ModuleExportsAnalyzer.modules(ModuleExportsAnalyzer.java:124)
at jdk.jdeps/com.sun.tools.jdeps.ModuleExportsAnalyzer.run(ModuleExportsAnalyzer.java:97)
at jdk.jdeps/com.sun.tools.jdeps.JdepsTask$ListModuleDeps.run(JdepsTask.java:1023)
at jdk.jdeps/com.sun.tools.jdeps.JdepsTask.run(JdepsTask.java:560)
at jdk.jdeps/com.sun.tools.jdeps.JdepsTask.run(JdepsTask.java:519)
at jdk.jdeps/com.sun.tools.jdeps.Main.main(Main.java:49)


CUSTOMER SUBMITTED WORKAROUND :
Additional info: unpacking and deeper analyzes shows the problem in PackagingDataCalculator.class:
`unzip logback-classic-1.2.3.jar -d logback-classic/`
`jdeps --list-reduced-deps logback-classic/ch/qos/logback/classic/spi/PackagingDataCalculator.class`

https://github.com/qos-ch/logback/blob/v_1.2.3/logback-classic/src/main/java/ch/qos/logback/classic/spi/PackagingDataCalculator.java#L20


FREQUENCY : always