[Libreoffice-commits] core.git: Branch 'libreoffice-6-4' - vcl/source

[Stephan Bergmann (via logerrit)]

 vcl/source/filter/jpeg/Exif.cxx |   16 ++++------------
 1 file changed, 4 insertions(+), 12 deletions(-)

New commits:
commit e06d40222222d98f6a21a0a60d1491e7126f151c
Author:     Stephan Bergmann <sbergman at redhat.com>
AuthorDate: Wed Apr 8 11:56:34 2020 +0200
Commit:     Michael Stahl <michael.stahl at cib.de>
CommitDate: Thu Apr 9 10:53:24 2020 +0200

    tdf#131969: Fix reading SHORT Orientation value
    
    <http://www.cipa.jp/std/documents/e/DC-008-2012_E.pdf> "CIPA DC- 008-Translation-
    2012: Exchangeable image file format for digital still cameras: Exif Version 2.3"
    documents that the Orientation tag 0x0112 expects a count of 1 values of type SHORT
    (16 bit), and details that values <= 4 bytes are stored in the Value Offset field
    always using bytes starting from the left of the field.
    
    This is a regression introduced with 42c0e433aca68c669bc0f55af404b6bae1655fba "Avoid
    -fsanitize=misaligned-pointer-use".  That commit had wondered why the original code
    had used OSL_SWAPWORD instead of OSL_SWAPDWORD when reading and writing such
    orientation values.  It turns out that that original code had happened to work
    correctly when processing either little or big endian data on a little endian
    machine.  (Though it would have worked incorrectly when processing either little or
    big endian data on a big endian machine.)  And with
    42c0e433aca68c669bc0f55af404b6bae1655fba, the code worked when processing little
    endian data on a little endian machine, but failed when processing big endian data
    on a little endian machine, as is the case for tdf#131669 on e.g. x86_64.
    
    (read32 has become unused and is thus removed.)
    
    Change-Id: I7992629048ac44c00ee703c75164f3d094773244
    Reviewed-on: https://gerrit.libreoffice.org/c/core/+/91881
    Tested-by: Jenkins
    Reviewed-by: Stephan Bergmann <sbergman at redhat.com>
    Reviewed-by: Tomaž Vajngerl <quikee at gmail.com>
    (cherry picked from commit fd5961cb0e2ebc2f5797f76a2b1f9fd52ca4b3ab)
    Reviewed-on: https://gerrit.libreoffice.org/c/core/+/91889
    Reviewed-by: Michael Stahl <michael.stahl at cib.de>

diff --git a/vcl/source/filter/jpeg/Exif.cxx b/vcl/source/filter/jpeg/Exif.cxx
index 6dd3bd1b2baa..b0f68a4aed40 100644
--- a/vcl/source/filter/jpeg/Exif.cxx
+++ b/vcl/source/filter/jpeg/Exif.cxx
@@ -169,16 +169,6 @@ void write16(sal_uInt16 value, sal_uInt8 (& data)[2], bool littleEndian) {
     }
 }
 
-sal_uInt32 read32(sal_uInt8 const (& data)[4], bool littleEndian) {
-    if (littleEndian) {
-        return data[0] | (sal_uInt32(data[1]) << 8)
-            | (sal_uInt32(data[2]) << 16) | (sal_uInt32(data[3]) << 24);
-    } else {
-        return data[3] | (sal_uInt32(data[2]) << 8)
-            | (sal_uInt32(data[1]) << 16) | (sal_uInt32(data[0]) << 24);
-    }
-}
-
 void write32(sal_uInt32 value, sal_uInt8 (& data)[4], bool littleEndian) {
     if (littleEndian) {
         data[0] = value & 0xFF;
@@ -210,11 +200,13 @@ void Exif::processIFD(sal_uInt8* pExifData, sal_uInt16 aLength, sal_uInt16 aOffs
             {
                 write16(3, ifd->type, littleEndian);
                 write32(1, ifd->count, littleEndian);
-                write32(maOrientation, ifd->offset, littleEndian);
+                write16(
+                    maOrientation, reinterpret_cast<sal_uInt8 (&)[2]>(ifd->offset), littleEndian);
             }
             else
             {
-                sal_uInt32 nIfdOffset = read32(ifd->offset, littleEndian);
+                sal_uInt16 nIfdOffset = read16(
+                    reinterpret_cast<sal_uInt8 (&)[2]>(ifd->offset), littleEndian);
                 maOrientation = convertToOrientation(nIfdOffset);
             }
         }