pdfium: only init pdfium library one and destroy on LO exit

With more and more usage of PDFium, it is hard to keep track of
the life-time of the PDFium library, so it can happen that a
FPDF_DestroyLibrary happens when we still have another instance
where PDFium is still use. The result of this is a crash. To
prevent this, just initialize the library once and delete, when
on LO exit.

This can be improved in the future to only keep the library
active when in actual use.

[ Leaving out the vector graphic search bits, the motivation is to just
have this in libreoffice-7-0, so that recent pdf sig verify improvements
can be backported. ]

(cherry picked from commit 067a8a954c8e1d8d6465a4ab5fb61e93f16c26c2)

Conflicts:
vcl/source/graphic/VectorGraphicSearch.cxx

Change-Id: I5c7e5de7f8b97d10efb394c67c7a61b976c8d57c
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/102226
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolanm@redhat.com>

1 files changed, 43 insertions, 0 deletions

diff --git a/include/vcl/filter/PDFiumLibrary.hxx b/include/vcl/filter/PDFiumLibrary.hxx
new file mode 100644
index 000000000000..bc7912c17e81
--- /dev/null
+++ b/include/vcl/filter/PDFiumLibrary.hxx
@@ -0,0 +1,43 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ */
+
+#pragma once
+
+#include <config_features.h>
+
+#if HAVE_FEATURE_PDFIUM
+
+#include <memory>
+#include <rtl/instance.hxx>
+#include <vcl/dllapi.h>
+
+namespace vcl::pdf
+{
+class VCL_DLLPUBLIC PDFium final
+{
+private:
+    PDFium(const PDFium&) = delete;
+    PDFium& operator=(const PDFium&) = delete;
+
+public:
+    PDFium();
+    ~PDFium();
+};
+
+struct PDFiumLibrary : public rtl::StaticWithInit<std::shared_ptr<PDFium>, PDFiumLibrary>
+{
+    std::shared_ptr<PDFium> operator()() { return std::make_shared<PDFium>(); }
+};
+
+} // namespace vcl::pdf
+
+#endif // HAVE_FEATURE_PDFIUM
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */