[PDFBOX-5471] NPE when Transparency Group is missing the BBox

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.0.26
• Fix Version/s: 2.0.27, 3.0.0 PDFBox
• Component/s: Rendering
• Assignee: Tilman Hausherr
• Reporter: Henry Iguaro
• Created: 04/Jul/22 05:10
• Updated: 29/Sep/22 17:57
• Resolved: 04/Jul/22 17:13

Description

Some files contain transparency groups with no BBox. When this happens, PDFBox rendering code throws a NullPointerException in the TransparencyGroup constructor:

 

// transform the bbox
GeneralPath transformedBox = form.getBBox().transform(transform);
                                  \_______/ 
                               NPE when its null

The following is a screenshot taken from pdf-debugger when trying to open a file with has this issue:

The stack trace:

java.lang.RuntimeException: java.util.concurrent.ExecutionException: java.lang.NullPointerException: Cannot invoke "org.apache.pdfbox.pdmodel.common.PDRectangle.transform(org.apache.pdfbox.util.Matrix)" because the return value of "org.apache.pdfbox.pdmodel.graphics.form.PDTransparencyGroup.getBBox()" is null
    org.apache.pdfbox.debugger.pagepane.PagePane$RenderWorker.done(PagePane.java:485)
    java.desktop/sun.swing.AccumulativeRunnable.run(AccumulativeRunnable.java:112)
    java.base/java.security.AccessController.doPrivileged(AccessController.java:391)
    java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
Caused by: java.util.concurrent.ExecutionException: java.lang.NullPointerException: Cannot invoke "org.apache.pdfbox.pdmodel.common.PDRectangle.transform(org.apache.pdfbox.util.Matrix)" because the return value of "org.apache.pdfbox.pdmodel.graphics.form.PDTransparencyGroup.getBBox()" is null
    org.apache.pdfbox.debugger.pagepane.PagePane$RenderWorker.done(PagePane.java:465)
    java.desktop/sun.swing.AccumulativeRunnable.run(AccumulativeRunnable.java:112)
    java.base/java.security.AccessController.doPrivileged(AccessController.java:391)
    java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
Caused by: java.lang.NullPointerException: Cannot invoke "org.apache.pdfbox.pdmodel.common.PDRectangle.transform(org.apache.pdfbox.util.Matrix)" because the return value of "org.apache.pdfbox.pdmodel.graphics.form.PDTransparencyGroup.getBBox()" is null
    org.apache.pdfbox.rendering.PageDrawer$TransparencyGroup.<init>(PageDrawer.java:1672)
    org.apache.pdfbox.rendering.PageDrawer$TransparencyGroup.<init>(PageDrawer.java:1637)
    org.apache.pdfbox.rendering.PageDrawer.showTransparencyGroupOnGraphics(PageDrawer.java:1575)
    org.apache.pdfbox.rendering.PageDrawer.showTransparencyGroup(PageDrawer.java:1553)
    org.apache.pdfbox.contentstream.operator.graphics.DrawObject.process(DrawObject.java:81)
    org.apache.pdfbox.contentstream.PDFStreamEngine.processOperator(PDFStreamEngine.java:966)
    org.apache.pdfbox.contentstream.PDFStreamEngine.processStreamOperators(PDFStreamEngine.java:541)
    org.apache.pdfbox.contentstream.PDFStreamEngine.processStream(PDFStreamEngine.java:516)
    org.apache.pdfbox.contentstream.PDFStreamEngine.processPage(PDFStreamEngine.java:155)
    org.apache.pdfbox.rendering.PageDrawer.drawPage(PageDrawer.java:279)
    org.apache.pdfbox.rendering.PDFRenderer.renderImage(PDFRenderer.java:355)
    org.apache.pdfbox.debugger.pagepane.PagePane$RenderWorker.doInBackground(PagePane.java:453)
    org.apache.pdfbox.debugger.pagepane.PagePane$RenderWorker.doInBackground(PagePane.java:435)
    java.base/java.lang.Thread.run(Thread.java:832)
 

The following is an example file that reproduces this problem:

getbbox-null.pdf

 

A potential fix PR: https://github.com/apache/pdfbox/pull/145

Issue Links

• links to: GitHub Pull Request #145