[Libreoffice-commits] core.git: drawinglayer/source

[Caolán McNamara (via logerrit)]

 drawinglayer/source/tools/emfppath.cxx |   38 ++++++++++++++++++++++++++-------
 1 file changed, 30 insertions(+), 8 deletions(-)

New commits:
commit 354d7ec99900ef5c17ac340e54b815c395dfb0a4
Author:     Caolán McNamara <caolanm at redhat.com>
AuthorDate: Fri Jan 3 20:26:24 2020 +0000
Commit:     Caolán McNamara <caolanm at redhat.com>
CommitDate: Sat Jan 4 15:31:03 2020 +0100

    cid#1456609 Operands don't affect result
    
    2.2.2.37 EmfPlusPointR Object has...
    
    "X (variable) This value MUST be specified by either an EmfPlusInteger7 object
    or an EmfPlusInteger15 object." and the same for Y. where variable is variable
    length.
    
    I think ReadInt32 isn't the right choice here and we need to read either one or
    two bytes, using the highbit of the first byte to determine if we need to
    read another byte.
    
    Change-Id: I60c0687403ff58dc393bd55a22f37c89357f60c3
    Reviewed-on: https://gerrit.libreoffice.org/c/core/+/86207
    Tested-by: Jenkins
    Reviewed-by: Caolán McNamara <caolanm at redhat.com>
    Tested-by: Caolán McNamara <caolanm at redhat.com>

diff --git a/drawinglayer/source/tools/emfppath.cxx b/drawinglayer/source/tools/emfppath.cxx
index 471cc6729cf3..0c1baa3d2634 100644
--- a/drawinglayer/source/tools/emfppath.cxx
+++ b/drawinglayer/source/tools/emfppath.cxx
@@ -23,14 +23,38 @@
 #include <sal/log.hxx>
 #include "emfppath.hxx"
 
+namespace
+{
+    const unsigned char nTopBitInt7 = 0x80;
+    const unsigned char nSignBitInt7 = 0x40;
+    // include the sign bit so if its negative we get
+    // that "missing" bit pre-set to 1
+    const unsigned char nValueMaskInt7 = 0x7F;
+}
+
 namespace emfplushelper
 {
-    static sal_Int16 GetEmfPlusInteger(sal_Int32 nInt)
+    // see 2.2.2.21 EmfPlusInteger7
+    //     2.2.2.22 EmfPlusInteger15
+    // and 2.2.2.37 EmfPlusPointR Object
+    static sal_Int16 GetEmfPlusInteger(SvStream& s)
     {
-        if (nInt & 0x80000000)
-            return (nInt & 0x7FFF) >> 16;
+        unsigned char u8(0);
+        s.ReadUChar(u8);
+
+        bool bIsEmfPlusInteger15 = u8 & nTopBitInt7;
+        bool bNegative = u8 & nSignBitInt7;
+        unsigned char val1 = u8 & nValueMaskInt7;
+        if (bNegative)
+            val1 |= nTopBitInt7;
+        if (!bIsEmfPlusInteger15)
+        {
+            return static_cast<signed char>(val1);
+        }
 
-        return nInt >> 24;
+        s.ReadUChar(u8);
+        sal_uInt16 nRet = (val1 << 8) | u8;
+        return static_cast<sal_Int16>(nRet);
     }
 
     EMFPPath::EMFPPath (sal_Int32 _nPoints, bool bLines)
@@ -60,10 +84,8 @@ namespace emfplushelper
                 // EMFPlusPointR: points are stored in EMFPlusInteger7 or
                 // EMFPlusInteger15 objects, see section 2.2.2.21/22
                 // If 0x800 bit is set, the 0x4000 bit is undefined and must be ignored
-                sal_Int32 x, y;
-                s.ReadInt32(x).ReadInt32(y);
-                x = GetEmfPlusInteger(x);
-                y = GetEmfPlusInteger(y);
+                sal_Int32 x = GetEmfPlusInteger(s);
+                sal_Int32 y = GetEmfPlusInteger(s);
                 pPoints [i*2] = x;
                 pPoints [i*2 + 1] = y;
                 SAL_INFO("drawinglayer", "EMF+\t\t\tEmfPlusPointR [x,y]: " << x << ", " << y);