From cb85d369b4f9772b6e203c843d427f9473f2b2f3 Mon Sep 17 00:00:00 2001
From: TinyServal <git@tinyserval.dev>
Date: Fri, 11 Apr 2025 15:49:27 +1000
Subject: [PATCH] Don't apply filters to empty stream objects

---
 libqpdf/QPDFWriter.cc | 6 ++++++
 1 file changed, 6 insertions(+), 0 deletions(-)

diff --git a/libqpdf/QPDFWriter.cc b/libqpdf/QPDFWriter.cc
index cf97ea3..1f9cd6b 100644
--- a/libqpdf/QPDFWriter.cc
+++ b/libqpdf/QPDFWriter.cc
@@ -1293,6 +1293,12 @@ QPDFWriter::willFilterStream(
         QTC::TC("qpdf", "QPDFWriter compressing uncompressed stream");
     }
 
+    // Disable compression for empty streams to improve compatibility
+    if (stream_dict.getKey("/Length").isInteger() && stream_dict.getKey("/Length").getIntValue() == 0) {
+        filter = true;
+        compress_stream = false;
+    }
+
     bool filtered = false;
     for (bool first_attempt: {true, false}) {
         PipelinePopper pp_stream_data(this);
--
libgit2 0.21.4