Add test validating that images in nested XObjects are included in optimization

The sample file (nested-images.pdf) includes a pdf with an image that is
nested within an XObject within an XObject in the Resources dict of the
only page. These images were ignored in prior versions of qpdf.

4 files changed, 22 insertions, 0 deletions

diff --git a/qpdf/qtest/image-optimization.test b/qpdf/qtest/image-optimization.test
index 1b3901e6..10ffd526 100644
--- a/qpdf/qtest/image-optimization.test
+++ b/qpdf/qtest/image-optimization.test
@@ -33,6 +33,8 @@ my @image_opt = (
     ['large-inline-image', 'inline-images-keep-all', '--keep-inline-images'],
     ['unsupported-optimization', 'unsupported',
      '--oi-min-width=0 --oi-min-height=0 --oi-min-area=0'],
+    ['nested-images', 'nested-images',
+     '--oi-min-width=0 --oi-min-height=0 --oi-min-area=0']
     );
 
 my $n_tests = 2 * scalar(@image_opt);
diff --git a/qpdf/qtest/qpdf/nested-images.pdf b/qpdf/qtest/qpdf/nested-images.pdf
new file mode 100644
index 00000000..cb2b4d87
--- /dev/null
+++ b/qpdf/qtest/qpdf/nested-images.pdf
diff --git a/qpdf/qtest/qpdf/optimize-images-nested-images-json.out b/qpdf/qtest/qpdf/optimize-images-nested-images-json.out
new file mode 100644
index 00000000..9f713aa7
--- /dev/null
+++ b/qpdf/qtest/qpdf/optimize-images-nested-images-json.out
@@ -0,0 +1,18 @@
+{
+  "version": 2,
+  "parameters": {
+    "decodelevel": "generalized"
+  },
+  "pages": [
+    {
+      "contents": [
+        "4 0 R"
+      ],
+      "images": [],
+      "label": null,
+      "object": "3 0 R",
+      "outlines": [],
+      "pageposfrom1": 1
+    }
+  ]
+}
diff --git a/qpdf/qtest/qpdf/optimize-images-nested-images.out b/qpdf/qtest/qpdf/optimize-images-nested-images.out
new file mode 100644
index 00000000..253a9208
--- /dev/null
+++ b/qpdf/qtest/qpdf/optimize-images-nested-images.out
@@ -0,0 +1,2 @@
+qpdf: image /X1 on page 1: optimizing image reduces size from 2628 to ...
+qpdf: wrote file a.pdf