From 31bde2f9d7517d3cf2433c2ea787eb9542532496 Mon Sep 17 00:00:00 2001 From: Jay Berkenbilt Date: Sun, 9 Jun 2019 17:19:07 -0400 Subject: Handle empty DecodeParams array for (fixes #331) On read, ignore /DecodeParms when empty list; on write, delete it. Some files have been found that include an empty list for /DecodeParms, but this is not technically compliant with the spec, and the only sensible interpretation is to treat it as if there are no decode parameters. --- libqpdf/QPDFWriter.cc | 8 ++++++++ libqpdf/QPDF_Stream.cc | 4 ++++ 2 files changed, 12 insertions(+) (limited to 'libqpdf') diff --git a/libqpdf/QPDFWriter.cc b/libqpdf/QPDFWriter.cc index fee287bc..0cc0547d 100644 --- a/libqpdf/QPDFWriter.cc +++ b/libqpdf/QPDFWriter.cc @@ -1604,6 +1604,14 @@ QPDFWriter::unparseObject(QPDFObjectHandle object, int level, // Suppress /Length since we will write it manually object.removeKey("/Length"); + // If /DecodeParms is an empty list, remove it. + if (object.getKey("/DecodeParms").isArray() && + (0 == object.getKey("/DecodeParms").getArrayNItems())) + { + QTC::TC("qpdf", "QPDFWriter remove empty DecodeParms"); + object.removeKey("/DecodeParms"); + } + if (flags & f_filtered) { // We will supply our own filter and decode diff --git a/libqpdf/QPDF_Stream.cc b/libqpdf/QPDF_Stream.cc index 3733940d..3ddb1498 100644 --- a/libqpdf/QPDF_Stream.cc +++ b/libqpdf/QPDF_Stream.cc @@ -391,6 +391,10 @@ QPDF_Stream::filterable(std::vector& filters, QPDFObjectHandle decode_obj = this->stream_dict.getKey("/DecodeParms"); std::vector decode_parms; + if (decode_obj.isArray() && (decode_obj.getArrayNItems() == 0)) + { + decode_obj = QPDFObjectHandle::newNull(); + } if (decode_obj.isArray()) { for (int i = 0; i < decode_obj.getArrayNItems(); ++i) -- cgit v1.2.3-54-g00ecf