[Libreoffice-commits] core.git: vcl/qa vcl/source

[Luboš Luňák (via logerrit)]

 vcl/qa/cppunit/svm/svmtest.cxx |    8 ++++----
 vcl/source/bitmap/salbmp.cxx   |   15 ++++++++++++++-
 2 files changed, 18 insertions(+), 5 deletions(-)

New commits:
commit b1c119679700630d16bcf76d96a99e3a39908914
Author:     Luboš Luňák <l.lunak at collabora.com>
AuthorDate: Tue Jun 30 09:38:43 2020 +0200
Commit:     Luboš Luňák <l.lunak at collabora.com>
CommitDate: Wed Jul 1 07:35:25 2020 +0200

    do not use scanline padding for computing vcl bitmap checksum
    
    This idea of checksums is still kind of broken (different RGB order
    or different scaling algorithm make the checksum different between
    different VCL backends). But at least don't include undefined
    garbage.
    
    Change-Id: Ia03bb960c50d3da51dad9b37de7a4f709d8ee206
    Reviewed-on: https://gerrit.libreoffice.org/c/core/+/97484
    Tested-by: Jenkins
    Reviewed-by: Luboš Luňák <l.lunak at collabora.com>

diff --git a/vcl/qa/cppunit/svm/svmtest.cxx b/vcl/qa/cppunit/svm/svmtest.cxx
index 413c3b7f69f4..9deed5e13c10 100644
--- a/vcl/qa/cppunit/svm/svmtest.cxx
+++ b/vcl/qa/cppunit/svm/svmtest.cxx
@@ -1012,10 +1012,10 @@ void SvmTest::checkBitmapExs(const GDIMetaFile& rMetaFile)
             "281fc589",
             "5e01ddcc",
             "4df0e464",
-            "34434a50",
-            "d1736327",
-            "b37875c2",
-            "a85d44b8",
+            "6c1263f9",
+            "747e8dfb",
+            "3c80d829",
+            "71efc447",
         });
     }
 
diff --git a/vcl/source/bitmap/salbmp.cxx b/vcl/source/bitmap/salbmp.cxx
index 3932c12b8ce7..6d955b6aa4d3 100644
--- a/vcl/source/bitmap/salbmp.cxx
+++ b/vcl/source/bitmap/salbmp.cxx
@@ -30,7 +30,20 @@ void SalBitmap::updateChecksum() const
     if (pBuf)
     {
         nCrc = pBuf->maPalette.GetChecksum();
-        nCrc = vcl_get_checksum(nCrc, pBuf->mpBits, pBuf->mnScanlineSize * pBuf->mnHeight);
+        const int bytesPerPixel = ( pBuf->mnBitCount + 7 ) / 8;
+        if( pBuf->mnFormat & ScanlineFormat::TopDown )
+        {
+            if( pBuf->mnScanlineSize == pBuf->mnWidth * bytesPerPixel )
+                nCrc = vcl_get_checksum(nCrc, pBuf->mpBits, pBuf->mnScanlineSize * pBuf->mnHeight);
+            else // Do not include padding with undefined content in the checksum.
+                for( long y = 0; y < pBuf->mnHeight; ++y )
+                    nCrc = vcl_get_checksum(nCrc, pBuf->mpBits + y * pBuf->mnScanlineSize, pBuf->mnWidth * bytesPerPixel);
+        }
+        else // Compute checksum in the order of scanlines, to make it consistent between different bitmap implementations.
+        {
+            for( long y = pBuf->mnHeight - 1; y >= 0; --y )
+                nCrc = vcl_get_checksum(nCrc, pBuf->mpBits + y * pBuf->mnScanlineSize, pBuf->mnWidth * bytesPerPixel);
+        }
         pThis->ReleaseBuffer(pBuf, BitmapAccessMode::Read);
         pThis->mnChecksum = nCrc;
         pThis->mbChecksumValid = true;