commit 6c1f0a25d5af6a403b4e851c18caf5d084c4a3d9
author Wil <wcarmon@users.noreply.github.com> Fri May 10 16:57:48 2019 +0200
committer Andreas Dangel <adangel@apache.org> Mon May 20 19:45:39 2019 +0200
tree c47fc516664fb454559cfa2f4497dd51ad14205e
parent e79d6fc25c6b87ada698551e75c70fe9ada3adf9

[MPMD-288] - NullPointerException when File.list() returns null

Closes #11

Fixed NullPointerException
this line throws NPE when file.list is null
https://docs.oracle.com/javase/8/docs/api/java/io/File.html#list--
For me this occurs on jar files like `~/.m2/repository/org/apache/logging/log4j/log4j-api/2.11.1/log4j-api-2.11.1.jar`

Contributed by: Wil Carmon

src/main/java/org/apache/maven/plugins/pmd/PmdReport.java

diff --git a/src/main/java/org/apache/maven/plugins/pmd/PmdReport.java b/src/main/java/org/apache/maven/plugins/pmd/PmdReport.java
index f88c89a..b3c5135 100644
--- a/src/main/java/org/apache/maven/plugins/pmd/PmdReport.java
+++ b/src/main/java/org/apache/maven/plugins/pmd/PmdReport.java
@@ -769,7 +769,9 @@
                         for ( String path : projectCompileClasspath )
                         {
                             File pathFile = new File( path );
-                            if ( !pathFile.exists() || pathFile.list().length == 0 )
+                            String[] children = pathFile.list();
+
+                            if ( !pathFile.exists() || ( children != null && children.length == 0 ) )
                             {
                                 getLog().warn( "The project " + localProject.getArtifactId()
                                     + " does not seem to be compiled. PMD results might be inaccurate." );