request for readme.md example usage "filtervalue" fix

[inkuxuan]

in line 451 of readme.md, the example goes

-filter keywords filtervalue [MATH-

While the parameter instructions (line 49) goes

-filtervalue

And I think only -filtervalue works because if I pass filtervalue as a parameter, it throws NullPointerException at fr.inria.coming.core.filter.commitmessage.KeyWordsMessageFilter#accept(Commit c) (line 36)

[martinezmatias]

Hi @inkuxuan

Could you create a Pull Request with a test that exposes the wrong behaviour?
Thanks
Matias

[inkuxuan]

@martinezmatias

Sorry but I was only able to build the project using Maven. Opening this project in my IDE will end up with Maven failing to download dependencies. Thus I am unable to modify and create a new test case.
I can give further information about the run though.

Microsoft Windows version 10.0.19042.1052

Java version output:

java version "1.8.0_241"
Java(TM) SE Runtime Environment (build 1.8.0_241-b07)
Java HotSpot(TM) 64-Bit Server VM (build 25.241-b07, mixed mode)

Command line:

java -classpath ./coming-with-dep.jar fr.inria.coming.main.ComingMain -location ../commons-math/ -mode mineinstance -pattern ./pattern_specification/pattern_DEL_IF_RET.xml -filter keywords filtervalue MATH- -output ./out

in which coming-with-dep.jar is the build output by mvn install -DskipTests;
../commons-math/ is the git repository cloned from https://github.com/apache/commons-math;
./pattern_specification directory has the same content as coming/src/main/resources/pattern_specification

The run will end up with the following lines of output:

Analyzing 6700/6799 1b7f10eed7ad4548b85e1449686206332ab4a78c
Exception in thread "main" java.lang.NullPointerException
at java.lang.String.contains(Unknown Source)
at fr.inria.coming.core.filter.commitmessage.KeyWordsMessageFilter.accept(KeyWordsMessageFilter.java:36)
at fr.inria.coming.core.filter.commitmessage.KeyWordsMessageFilter.accept(KeyWordsMessageFilter.java:11)
at fr.inria.coming.core.engine.RevisionNavigationExperiment.accept(RevisionNavigationExperiment.java:160)
at fr.inria.coming.core.engine.RevisionNavigationExperiment.analyze(RevisionNavigationExperiment.java:120)
at fr.inria.coming.main.ComingMain.start(ComingMain.java:147)
at fr.inria.coming.main.ComingMain.run(ComingMain.java:140)
at fr.inria.coming.main.ComingMain.main(ComingMain.java:124)