pdfium: add an FPDFBitmap_Create() wrapper

Fixes a leak in PDFiumPage::getChecksum().

Change-Id: I57471a26702f1d3dd69e9e18a4067ce0e724e358
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/104386
Tested-by: Jenkins
Reviewed-by: Miklos Vajna <vmiklos@collabora.com>

2 files changed, 37 insertions, 20 deletions

diff --git a/vcl/source/filter/ipdf/pdfread.cxx b/vcl/source/filter/ipdf/pdfread.cxx
index 5e113ff2aba8..605ea45f8c23 100644
--- a/vcl/source/filter/ipdf/pdfread.cxx
+++ b/vcl/source/filter/ipdf/pdfread.cxx
@@ -155,24 +155,24 @@ size_t RenderPDFBitmaps(const void* pBuffer, int nSize, std::vector<Bitmap>& rBi
     auto pPdfium = vcl::pdf::PDFiumLibrary::get();
 
     // Load the buffer using pdfium.
-    FPDF_DOCUMENT pPdfDocument = FPDF_LoadMemDocument(pBuffer, nSize, /*password=*/nullptr);
+    std::unique_ptr<vcl::pdf::PDFiumDocument> pPdfDocument = pPdfium->openDocument(pBuffer, nSize);
     if (!pPdfDocument)
         return 0;
 
-    const int nPageCount = FPDF_GetPageCount(pPdfDocument);
+    const int nPageCount = pPdfDocument->getPageCount();
     if (nPages <= 0)
         nPages = nPageCount;
     const size_t nLastPage = std::min<int>(nPageCount, nFirstPage + nPages) - 1;
     for (size_t nPageIndex = nFirstPage; nPageIndex <= nLastPage; ++nPageIndex)
     {
         // Render next page.
-        FPDF_PAGE pPdfPage = FPDF_LoadPage(pPdfDocument, nPageIndex);
+        std::unique_ptr<vcl::pdf::PDFiumPage> pPdfPage = pPdfDocument->openPage(nPageIndex);
         if (!pPdfPage)
             break;
 
         // Calculate the bitmap size in points.
-        size_t nPageWidthPoints = FPDF_GetPageWidth(pPdfPage);
-        size_t nPageHeightPoints = FPDF_GetPageHeight(pPdfPage);
+        size_t nPageWidthPoints = pPdfPage->getWidth();
+        size_t nPageHeightPoints = pPdfPage->getHeight();
         if (pSizeHint && pSizeHint->getX() && pSizeHint->getY())
         {
             // Have a size hint, prefer that over the logic size from the PDF.
@@ -183,21 +183,24 @@ size_t RenderPDFBitmaps(const void* pBuffer, int nSize, std::vector<Bitmap>& rBi
         // Returned unit is points, convert that to pixel.
         const size_t nPageWidth = pointToPixel(nPageWidthPoints, fResolutionDPI);
         const size_t nPageHeight = pointToPixel(nPageHeightPoints, fResolutionDPI);
-        FPDF_BITMAP pPdfBitmap = FPDFBitmap_Create(nPageWidth, nPageHeight, /*alpha=*/1);
+        std::unique_ptr<vcl::pdf::PDFiumBitmap> pPdfBitmap
+            = pPdfium->createBitmap(nPageWidth, nPageHeight, /*alpha=*/1);
         if (!pPdfBitmap)
             break;
 
-        const FPDF_DWORD nColor = FPDFPage_HasTransparency(pPdfPage) ? 0x00000000 : 0xFFFFFFFF;
-        FPDFBitmap_FillRect(pPdfBitmap, 0, 0, nPageWidth, nPageHeight, nColor);
-        FPDF_RenderPageBitmap(pPdfBitmap, pPdfPage, /*start_x=*/0, /*start_y=*/0, nPageWidth,
-                              nPageHeight, /*rotate=*/0, /*flags=*/0);
+        const FPDF_DWORD nColor
+            = FPDFPage_HasTransparency(pPdfPage->getPointer()) ? 0x00000000 : 0xFFFFFFFF;
+        FPDFBitmap_FillRect(pPdfBitmap->getPointer(), 0, 0, nPageWidth, nPageHeight, nColor);
+        FPDF_RenderPageBitmap(pPdfBitmap->getPointer(), pPdfPage->getPointer(), /*start_x=*/0,
+                              /*start_y=*/0, nPageWidth, nPageHeight, /*rotate=*/0, /*flags=*/0);
 
         // Save the buffer as a bitmap.
         Bitmap aBitmap(Size(nPageWidth, nPageHeight), 24);
         {
             BitmapScopedWriteAccess pWriteAccess(aBitmap);
-            const auto pPdfBuffer = static_cast<ConstScanline>(FPDFBitmap_GetBuffer(pPdfBitmap));
-            const int nStride = FPDFBitmap_GetStride(pPdfBitmap);
+            const auto pPdfBuffer
+                = static_cast<ConstScanline>(FPDFBitmap_GetBuffer(pPdfBitmap->getPointer()));
+            const int nStride = FPDFBitmap_GetStride(pPdfBitmap->getPointer());
             for (size_t nRow = 0; nRow < nPageHeight; ++nRow)
             {
                 ConstScanline pPdfLine = pPdfBuffer + (nStride * nRow);
@@ -207,12 +210,8 @@ size_t RenderPDFBitmaps(const void* pBuffer, int nSize, std::vector<Bitmap>& rBi
         }
 
         rBitmaps.emplace_back(std::move(aBitmap));
-        FPDFBitmap_Destroy(pPdfBitmap);
-        FPDF_ClosePage(pPdfPage);
     }
 
-    FPDF_CloseDocument(pPdfDocument);
-
     return rBitmaps.size();
 #else
     (void)pBuffer;
diff --git a/vcl/source/pdf/PDFiumLibrary.cxx b/vcl/source/pdf/PDFiumLibrary.cxx
index 64fdd6a7e0d4..32c33580d1df 100644
--- a/vcl/source/pdf/PDFiumLibrary.cxx
+++ b/vcl/source/pdf/PDFiumLibrary.cxx
@@ -139,6 +139,21 @@ std::unique_ptr<PDFiumDocument> PDFium::openDocument(const void* pData, int nSiz
     return pPDFiumDocument;
 }
 
+std::unique_ptr<PDFiumBitmap> PDFium::createBitmap(int nWidth, int nHeight, int nAlpha)
+{
+    std::unique_ptr<PDFiumBitmap> pPDFiumBitmap;
+    FPDF_BITMAP pPdfBitmap = FPDFBitmap_Create(nWidth, nHeight, nAlpha);
+    if (!pPdfBitmap)
+    {
+        maLastError = "Failed to create bitmap";
+    }
+    else
+    {
+        pPDFiumBitmap = std::make_unique<PDFiumBitmap>(pPdfBitmap);
+    }
+    return pPDFiumBitmap;
+}
+
 PDFiumDocument::PDFiumDocument(FPDF_DOCUMENT pPdfDocument)
     : mpPdfDocument(pPdfDocument)
 {
@@ -377,7 +392,8 @@ BitmapChecksum PDFiumPage::getChecksum()
 {
     size_t nPageWidth = getWidth();
     size_t nPageHeight = getHeight();
-    FPDF_BITMAP pPdfBitmap = FPDFBitmap_Create(nPageWidth, nPageHeight, /*alpha=*/1);
+    auto pPdfBitmap
+        = std::make_unique<PDFiumBitmap>(FPDFBitmap_Create(nPageWidth, nPageHeight, /*alpha=*/1));
     if (!pPdfBitmap)
     {
         return 0;
@@ -385,13 +401,15 @@ BitmapChecksum PDFiumPage::getChecksum()
 
     // Intentionally not using FPDF_ANNOT here, annotations/commenting is OK to not affect the
     // checksum, signature verification wants this.
-    FPDF_RenderPageBitmap(pPdfBitmap, mpPage, /*start_x=*/0, /*start_y=*/0, nPageWidth, nPageHeight,
+    FPDF_RenderPageBitmap(pPdfBitmap->getPointer(), mpPage, /*start_x=*/0, /*start_y=*/0,
+                          nPageWidth, nPageHeight,
                           /*rotate=*/0, /*flags=*/0);
     Bitmap aBitmap(Size(nPageWidth, nPageHeight), 24);
     {
         BitmapScopedWriteAccess pWriteAccess(aBitmap);
-        const auto pPdfBuffer = static_cast<ConstScanline>(FPDFBitmap_GetBuffer(pPdfBitmap));
-        const int nStride = FPDFBitmap_GetStride(pPdfBitmap);
+        const auto pPdfBuffer
+            = static_cast<ConstScanline>(FPDFBitmap_GetBuffer(pPdfBitmap->getPointer()));
+        const int nStride = FPDFBitmap_GetStride(pPdfBitmap->getPointer());
         for (size_t nRow = 0; nRow < nPageHeight; ++nRow)
         {
             ConstScanline pPdfLine = pPdfBuffer + (nStride * nRow);