[PDFBOX-5795] Crash for Softmask with incorrect backdrop color components

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.0.31, 3.0.2 PDFBox
• Fix Version/s: 2.0.32, 3.0.3 PDFBox, 4.0.0
• Component/s: Rendering
• Flags: Patch
• Assignee: Tilman Hausherr
• Reporter: Daniel Persson
• Created: 02/Apr/24 11:49
• Updated: 02/Apr/24 13:13
• Resolved: 02/Apr/24 13:13

Description

This error occured in our production of an old archive. None of the files crashed in any other viewer (Chrome, Adobe, Firefox, Poppler a.s.o). 

 

I've read up on the subject in the 1.7 specification, and it seems like PDFBox is following the specification, but not being able to open these files seems a bit too strict.

 

The easiest way to reproduce is just to open the attached file with the debugger.

java -jar debugger-app-4.0.0-SNAPSHOT.jar borsen-2065-20111030-1-p4.pdf 

The application will crash with this exception:

Caused by: java.lang.ArrayIndexOutOfBoundsException: Index 1 out of bounds for length 1
    org.apache.pdfbox.pdmodel.graphics.color.PDColor.toRGB(PDColor.java:155)
    org.apache.pdfbox.rendering.PageDrawer$TransparencyGroup.<init>(PageDrawer.java:1696)
    org.apache.pdfbox.rendering.PageDrawer$TransparencyGroup.<init>(PageDrawer.java:1573)
    org.apache.pdfbox.rendering.PageDrawer.applySoftMaskToPaint(PageDrawer.java:604)
    org.apache.pdfbox.rendering.PageDrawer.showTransparencyGroupOnGraphics(PageDrawer.java:1549)
    org.apache.pdfbox.rendering.PageDrawer.showTransparencyGroup(PageDrawer.java:1489)
    org.apache.pdfbox.contentstream.operator.graphics.DrawObject.process(DrawObject.java:81)
    org.apache.pdfbox.contentstream.PDFStreamEngine.processOperator(PDFStreamEngine.java:872)
    org.apache.pdfbox.contentstream.PDFStreamEngine.processStreamOperators(PDFStreamEngine.java:511)
    org.apache.pdfbox.contentstream.PDFStreamEngine.processStream(PDFStreamEngine.java:489)
    org.apache.pdfbox.contentstream.PDFStreamEngine.processPage(PDFStreamEngine.java:158)
    org.apache.pdfbox.rendering.PageDrawer.drawPage(PageDrawer.java:270)
    org.apache.pdfbox.rendering.PDFRenderer.renderImage(PDFRenderer.java:346)
    org.apache.pdfbox.debugger.pagepane.PagePane$RenderWorker.doInBackground(PagePane.java:527)
    org.apache.pdfbox.debugger.pagepane.PagePane$RenderWorker.doInBackground(PagePane.java:506)
    java.base/java.lang.Thread.run(Thread.java:833)
 

My solution, added as a patch, is to add a fallback to the colorspace available in the graphical context. This is working for the files I've tried so far.