pdfium: only init pdfium library once 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/+/102317
Tested-by: Miklos Vajna <vmiklos@collabora.com>
Reviewed-by: Miklos Vajna <vmiklos@collabora.com>

2 files changed, 41 insertions, 21 deletions

diff --git a/vcl/source/filter/ipdf/pdfread.cxx b/vcl/source/filter/ipdf/pdfread.cxx
index 6ace744ec1eb..5401bf3734a3 100644
--- a/vcl/source/filter/ipdf/pdfread.cxx
+++ b/vcl/source/filter/ipdf/pdfread.cxx
@@ -21,6 +21,8 @@
 #include <bitmapwriteaccess.hxx>
 #include <unotools/ucbstreamhelper.hxx>
 
+#include <vcl/filter/PDFiumLibrary.hxx>
+
 using namespace com::sun::star;
 
 namespace
@@ -95,12 +97,7 @@ bool getCompatibleStream(SvStream& rInStream, SvStream& rOutStream, sal_uInt64 n
     else
     {
         // Downconvert to PDF-1.5.
-        FPDF_LIBRARY_CONFIG aConfig;
-        aConfig.version = 2;
-        aConfig.m_pUserFontPaths = nullptr;
-        aConfig.m_pIsolate = nullptr;
-        aConfig.m_v8EmbedderSlot = 0;
-        FPDF_InitLibraryWithConfig(&aConfig);
+        auto pPdfium = vcl::pdf::PDFiumLibrary::get();
 
         // Read input into a buffer.
         SvMemoryStream aInBuffer;
@@ -121,7 +118,6 @@ bool getCompatibleStream(SvStream& rInStream, SvStream& rOutStream, sal_uInt64 n
             return false;
 
         FPDF_CloseDocument(pPdfDocument);
-        FPDF_DestroyLibrary();
 
         aWriter.m_aStream.Seek(STREAM_SEEK_TO_BEGIN);
         rOutStream.WriteStream(aWriter.m_aStream);
@@ -152,12 +148,7 @@ size_t RenderPDFBitmaps(const void* pBuffer, int nSize, std::vector<Bitmap>& rBi
                         const size_t nFirstPage, int nPages, const double fResolutionDPI)
 {
 #if HAVE_FEATURE_PDFIUM
-    FPDF_LIBRARY_CONFIG aConfig;
-    aConfig.version = 2;
-    aConfig.m_pUserFontPaths = nullptr;
-    aConfig.m_pIsolate = nullptr;
-    aConfig.m_v8EmbedderSlot = 0;
-    FPDF_InitLibraryWithConfig(&aConfig);
+    auto pPdfium = vcl::pdf::PDFiumLibrary::get();
 
     // Load the buffer using pdfium.
     FPDF_DOCUMENT pPdfDocument = FPDF_LoadMemDocument(pBuffer, nSize, /*password=*/nullptr);
@@ -207,7 +198,6 @@ size_t RenderPDFBitmaps(const void* pBuffer, int nSize, std::vector<Bitmap>& rBi
     }
 
     FPDF_CloseDocument(pPdfDocument);
-    FPDF_DestroyLibrary();
 
     return rBitmaps.size();
 #else
@@ -305,12 +295,7 @@ size_t ImportPDFUnloaded(const OUString& rURL, std::vector<std::pair<Graphic, Si
     std::shared_ptr<GfxLink> pGfxLink(std::make_shared<GfxLink>(
         std::move(pGraphicContent), nGraphicContentSize, GfxLinkType::NativePdf));
 
-    FPDF_LIBRARY_CONFIG aConfig;
-    aConfig.version = 2;
-    aConfig.m_pUserFontPaths = nullptr;
-    aConfig.m_pIsolate = nullptr;
-    aConfig.m_v8EmbedderSlot = 0;
-    FPDF_InitLibraryWithConfig(&aConfig);
+    auto pPdfium = vcl::pdf::PDFiumLibrary::get();
 
     // Load the buffer using pdfium.
     FPDF_DOCUMENT pPdfDocument
@@ -348,7 +333,6 @@ size_t ImportPDFUnloaded(const OUString& rURL, std::vector<std::pair<Graphic, Si
     }
 
     FPDF_CloseDocument(pPdfDocument);
-    FPDF_DestroyLibrary();
 
     return rGraphics.size();
 #else
diff --git a/vcl/source/pdf/PDFiumLibrary.cxx b/vcl/source/pdf/PDFiumLibrary.cxx
new file mode 100644
index 000000000000..604807524bf9
--- /dev/null
+++ b/vcl/source/pdf/PDFiumLibrary.cxx
@@ -0,0 +1,36 @@
+/* -*- 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/.
+ *
+ */
+
+#include <config_features.h>
+
+#if HAVE_FEATURE_PDFIUM
+
+#include <vcl/filter/PDFiumLibrary.hxx>
+#include <fpdf_doc.h>
+
+namespace vcl::pdf
+{
+PDFium::PDFium()
+{
+    FPDF_LIBRARY_CONFIG aConfig;
+    aConfig.version = 2;
+    aConfig.m_pUserFontPaths = nullptr;
+    aConfig.m_pIsolate = nullptr;
+    aConfig.m_v8EmbedderSlot = 0;
+    FPDF_InitLibraryWithConfig(&aConfig);
+}
+
+PDFium::~PDFium() { FPDF_DestroyLibrary(); }
+
+} // end vcl::pdf
+
+#endif // HAVE_FEATURE_PDFIUM
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */