Don't prune resource dictionaries on errors or by request

If we are unable to filter a page's content streams, don't attempt to
remove objects from the page's resource dictionary. Also provide a
command line option to suppress resource removal in case we ever need
this as a workaround for some bug or broken PDF files.

1 files changed, 11 insertions, 1 deletions

diff --git a/libqpdf/QPDFPageObjectHelper.cc b/libqpdf/QPDFPageObjectHelper.cc
index e9e09d73..4093622d 100644
--- a/libqpdf/QPDFPageObjectHelper.cc
+++ b/libqpdf/QPDFPageObjectHelper.cc
@@ -122,7 +122,17 @@ void
 QPDFPageObjectHelper::removeUnreferencedResources()
 {
     NameWatcher nw;
-    filterPageContents(&nw);
+    try
+    {
+        filterPageContents(&nw);
+    }
+    catch (std::exception& e)
+    {
+        this->oh.warnIfPossible(
+            std::string("Unable to parse content stream: ") + e.what() +
+            "; not attempting to remove unreferenced objects from this page");
+        return;
+    }
     // Walk through /Font and /XObject dictionaries, removing any
     // resources that are not referenced. We must make copies of
     // resource dictionaries down into the dictionaries are mutating