Hi, again. It seems that TTFSubsetter.buildGlyfTable() iterates on glyphIds, but inside the loop glyphIds is modified. This is why it may fail. Concurrent modification detection is not guaranteed to always work, even if it is fail-fast, though I doubt this is such a case. Modification of glyphIds inside the loop should not happen.
Regards, Constantine -- There is a computer disease that anybody who works with computers knows about. It's a very serious disease and it interferes completely with the work. The trouble with computers is that you 'play' with them! - Richard P. Feynman On Tue, Oct 21, 2025 at 7:37 AM Andreas Lehmkühler <[email protected]> wrote: > Hi, > > sounds like a concurrency issue. What exactly are you doing? Maybe > something with multiple threads working with the same document? > > Andreas > > Am 20.10.25 um 17:41 schrieb Constantine Dokolas: > > Hi there! > > > > I keep getting this exception when subsetting NotoSansDevanagari-Regular > > with PDFBox 3.0.5: > > > > Exception in thread "main" java.util.ConcurrentModificationException > >> at > >> > java.base/java.util.TreeMap$PrivateEntryIterator.nextEntry(TreeMap.java:1486) > >> at java.base/java.util.TreeMap$KeyIterator.next(TreeMap.java:1540) > >> at > >> > org.apache.fontbox.ttf.TTFSubsetter.buildGlyfTable(TTFSubsetter.java:617) > >> at > >> > org.apache.fontbox.ttf.TTFSubsetter.writeToStream(TTFSubsetter.java:1030) > >> at > >> > org.apache.pdfbox.pdmodel.font.TrueTypeEmbedder.subset(TrueTypeEmbedder.java:346) > >> at > >> org.apache.pdfbox.pdmodel.font.PDType0Font.subset(PDType0Font.java:304) > >> at > >> > org.apache.pdfbox.pdmodel.PDDocument.subsetDesignatedFonts(PDDocument.java:1064) > >> at org.apache.pdfbox.pdmodel.PDDocument.save(PDDocument.java:1052) > > > > > > Could this be related to PDFBOX-5918 > > <https://issues.apache.org/jira/browse/PDFBOX-5918>? > > > > Thanks in advance, > > Constantine > > > > -- > > There is a computer disease that anybody who works with computers knows > > about. It's a very serious disease and it interferes completely with the > > work. The trouble with computers is that you 'play' with them! > > - Richard P. Feynman > > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [email protected] > For additional commands, e-mail: [email protected] > >
