Sebastian Lackner : oleaut32: Fix possible integer overflow in VarR4FromDec.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: 728076223812e11441f1f185c30d836c1269712e
URL:    http://source.winehq.org/git/wine.git/?a=commit;h=728076223812e11441f1f185c3...

Author: Sebastian Lackner 
Date:   Wed Aug 19 06:51:49 2015 +0200

oleaut32: Fix possible integer overflow in VarR4FromDec.

---

dlls/oleaut32/tests/vartype.c | 3 ++-
 dlls/oleaut32/vartype.c       | 8 ++++----
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/dlls/oleaut32/tests/vartype.c b/dlls/oleaut32/tests/vartype.c
index 4dd77a0..7cbb059 100644
--- a/dlls/oleaut32/tests/vartype.c
+++ b/dlls/oleaut32/tests/vartype.c
@@ -2890,7 +2890,8 @@ static void test_VarR4FromDec(void)

CONVERT_DEC(VarR4FromDec,2,0x80,0,3276800); EXPECT(-32768.0f);
   CONVERT_DEC(VarR4FromDec,2,0,0,3276700);    EXPECT(32767.0f);
-  
+  CONVERT_DEC(VarR4FromDec,10,0,0,3276700);   EXPECT(0.00032767f);
+
   CONVERT_DEC(VarR4FromDec,0,0,1,0);        EXPECT(18446744073709551616.0f);
 }

diff --git a/dlls/oleaut32/vartype.c b/dlls/oleaut32/vartype.c
index 607d1a2..bf7ebc6 100644
--- a/dlls/oleaut32/vartype.c
+++ b/dlls/oleaut32/vartype.c
@@ -2948,28 +2948,28 @@ HRESULT WINAPI VarR4FromUI4(ULONG ulIn, float *pFltOut)
 HRESULT WINAPI VarR4FromDec(DECIMAL* pDecIn, float *pFltOut)
 {
   BYTE scale = DEC_SCALE(pDecIn);
-  int divisor = 1;
+  double divisor = 1.0;
   double highPart;

if (scale > DEC_MAX_SCALE || DEC_SIGN(pDecIn) & ~DECIMAL_NEG)
     return E_INVALIDARG;

while (scale--)
-    divisor *= 10;
+    divisor *= 10.0;

if (DEC_SIGN(pDecIn))
     divisor = -divisor;

if (DEC_HI32(pDecIn))
   {
-    highPart = (double)DEC_HI32(pDecIn) / (double)divisor;
+    highPart = (double)DEC_HI32(pDecIn) / divisor;
     highPart *= 4294967296.0F;
     highPart *= 4294967296.0F;
   }
   else
     highPart = 0.0;

-  *pFltOut = (double)DEC_LO64(pDecIn) / (double)divisor + highPart;
+  *pFltOut = (double)DEC_LO64(pDecIn) / divisor + highPart;
   return S_OK;
 }