vcl/source/filter/png/PngImageReader.cxx | 60 ++++++++++++++++++++++++-------
1 file changed, 47 insertions(+), 13 deletions(-)
New commits:
commit da4de084d20116f0ae49b43cd454188fde2ddac9
Author: Luboš Luňák <l.lu...@collabora.com>
AuthorDate: Fri Mar 5 19:38:07 2021 +0100
Commit: Luboš Luňák <l.lu...@collabora.com>
CommitDate: Fri Mar 12 15:35:16 2021 +0100
make PngImageReader return partially broken images
This makes it consistent with PNGReader, which is capable of reading
in e.g. the invalid-chunk.png test file.
Change-Id: Ia3b5553e588ac5778fad6de5bc284d5822febbda
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/112038
Reviewed-by: Tomaž Vajngerl <qui...@gmail.com>
Reviewed-by: Luboš Luňák <l.lu...@collabora.com>
Tested-by: Jenkins
diff --git a/vcl/source/filter/png/PngImageReader.cxx
b/vcl/source/filter/png/PngImageReader.cxx
index be94f99b04d2..ad778bce6aba 100644
--- a/vcl/source/filter/png/PngImageReader.cxx
+++ b/vcl/source/filter/png/PngImageReader.cxx
@@ -33,7 +33,11 @@ void lclReadStream(png_structp pPng, png_bytep pOutBytes,
png_size_t nBytesToRea
sal_Size nBytesRead = pStream->ReadBytes(pOutBytes, nBytesToRead);
if (nBytesRead != nBytesToRead)
- png_error(pPng, "Error reading");
+ {
+ // Make sure to not reuse old data (could cause infinite loop).
+ memset(pOutBytes + nBytesRead, 0, nBytesToRead - nBytesRead);
+ png_warning(pPng, "Error reading");
+ }
}
bool reader(SvStream& rStream, BitmapEx& rBitmapEx, bool bUseBitmap32)
@@ -61,9 +65,32 @@ bool reader(SvStream& rStream, BitmapEx& rBitmapEx, bool
bUseBitmap32)
return false;
}
+ // All variables holding resources need to be declared here in order to be
+ // properly cleaned up in case of an error, otherwise libpng's longjmp()
+ // jumps over the destructor calls.
+ Bitmap aBitmap;
+ AlphaMask aBitmapAlpha;
+ Size prefSize;
+ BitmapScopedWriteAccess pWriteAccess;
+ AlphaScopedWriteAccess pWriteAccessAlpha;
+ std::vector<std::vector<png_byte>> aRows;
+
if (setjmp(png_jmpbuf(pPng)))
{
png_destroy_read_struct(&pPng, &pInfo, nullptr);
+ // Set the bitmap if it contains something, even on failure. This
allows
+ // reading images that are only partially broken.
+ pWriteAccess.reset();
+ pWriteAccessAlpha.reset();
+ if (!aBitmap.IsEmpty() && !aBitmapAlpha.IsEmpty())
+ rBitmapEx = BitmapEx(aBitmap, aBitmapAlpha);
+ else if (!aBitmap.IsEmpty())
+ rBitmapEx = BitmapEx(aBitmap);
+ if (!rBitmapEx.IsEmpty() && !prefSize.IsEmpty())
+ {
+ rBitmapEx.SetPrefMapMode(MapMode(MapUnit::Map100thMM));
+ rBitmapEx.SetPrefSize(prefSize);
+ }
return false;
}
@@ -133,7 +160,6 @@ bool reader(SvStream& rStream, BitmapEx& rBitmapEx, bool
bUseBitmap32)
return false;
}
- Size prefSize;
png_uint_32 res_x = 0;
png_uint_32 res_y = 0;
int unit_type = 0;
@@ -150,14 +176,15 @@ bool reader(SvStream& rStream, BitmapEx& rBitmapEx, bool
bUseBitmap32)
{
size_t aRowSizeBytes = png_get_rowbytes(pPng, pInfo);
- Bitmap aBitmap(Size(width, height), 24);
+ aBitmap = Bitmap(Size(width, height), 24);
+ aBitmap.Erase(COL_WHITE);
{
- BitmapScopedWriteAccess pWriteAccess(aBitmap);
+ pWriteAccess = BitmapScopedWriteAccess(aBitmap);
ScanlineFormat eFormat = pWriteAccess->GetScanlineFormat();
if (eFormat == ScanlineFormat::N24BitTcBgr)
png_set_bgr(pPng);
- std::vector<std::vector<png_byte>> aRows(height);
+ aRows = std::vector<std::vector<png_byte>>(height);
for (auto& rRow : aRows)
rRow.resize(aRowSizeBytes, 0);
@@ -177,6 +204,7 @@ bool reader(SvStream& rStream, BitmapEx& rBitmapEx, bool
bUseBitmap32)
}
}
}
+ pWriteAccess.reset();
}
rBitmapEx = BitmapEx(aBitmap);
}
@@ -186,9 +214,10 @@ bool reader(SvStream& rStream, BitmapEx& rBitmapEx, bool
bUseBitmap32)
if (bUseBitmap32)
{
- Bitmap aBitmap(Size(width, height), 32);
+ aBitmap = Bitmap(Size(width, height), 32);
+ aBitmap.Erase(COL_WHITE);
{
- BitmapScopedWriteAccess pWriteAccess(aBitmap);
+ pWriteAccess = BitmapScopedWriteAccess(aBitmap);
ScanlineFormat eFormat = pWriteAccess->GetScanlineFormat();
if (eFormat == ScanlineFormat::N32BitTcAbgr
|| eFormat == ScanlineFormat::N32BitTcBgra)
@@ -196,7 +225,7 @@ bool reader(SvStream& rStream, BitmapEx& rBitmapEx, bool
bUseBitmap32)
png_set_bgr(pPng);
}
- std::vector<std::vector<png_byte>> aRows(height);
+ aRows = std::vector<std::vector<png_byte>>(height);
for (auto& rRow : aRows)
rRow.resize(aRowSizeBytes, 0);
@@ -227,22 +256,25 @@ bool reader(SvStream& rStream, BitmapEx& rBitmapEx, bool
bUseBitmap32)
}
}
}
+ pWriteAccess.reset();
}
rBitmapEx = BitmapEx(aBitmap);
}
else
{
- Bitmap aBitmap(Size(width, height), 24);
- AlphaMask aBitmapAlpha(Size(width, height), nullptr);
+ aBitmap = Bitmap(Size(width, height), 24);
+ aBitmapAlpha = AlphaMask(Size(width, height), nullptr);
+ aBitmap.Erase(COL_WHITE);
+ aBitmapAlpha.Erase(0xff); // transparent
{
- BitmapScopedWriteAccess pWriteAccess(aBitmap);
+ pWriteAccess = BitmapScopedWriteAccess(aBitmap);
ScanlineFormat eFormat = pWriteAccess->GetScanlineFormat();
if (eFormat == ScanlineFormat::N24BitTcBgr)
png_set_bgr(pPng);
- AlphaScopedWriteAccess pWriteAccessAlpha(aBitmapAlpha);
+ pWriteAccessAlpha = AlphaScopedWriteAccess(aBitmapAlpha);
- std::vector<std::vector<png_byte>> aRows(height);
+ aRows = std::vector<std::vector<png_byte>>(height);
for (auto& rRow : aRows)
rRow.resize(aRowSizeBytes, 0);
@@ -265,6 +297,8 @@ bool reader(SvStream& rStream, BitmapEx& rBitmapEx, bool
bUseBitmap32)
}
}
}
+ pWriteAccess.reset();
+ pWriteAccessAlpha.reset();
}
rBitmapEx = BitmapEx(aBitmap, aBitmapAlpha);
}
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