oleaut32: Fix rounding.

dlls/oleaut32/tests/varformat.c

@@ -381,8 +381,14 @@ static void test_VarFormat(void)
   VARFMT(VT_R8,V_R8,-0.1,".#",S_OK,"-.1");
   VARFMT(VT_R8,V_R8,0.099,"#.#",S_OK,".1");
   VARFMT(VT_R8,V_R8,0.0999,"#.##",S_OK,".1");
-  /* for large negative exponents, wine truncates instead of rounding */
-  todo_wine VARFMT(VT_R8,V_R8,0.099,"#.##",S_OK,".1");
+  VARFMT(VT_R8,V_R8,0.099,"#.##",S_OK,".1");
+  VARFMT(VT_R8,V_R8,0.0099,"#.##",S_OK,".01");
+  VARFMT(VT_R8,V_R8,0.0049,"#.##",S_OK,".");
+  VARFMT(VT_R8,V_R8,0.0094,"#.##",S_OK,".01");
+  VARFMT(VT_R8,V_R8,0.00099,"#.##",S_OK,".");
+  VARFMT(VT_R8,V_R8,0.0995,"#.##",S_OK,".1");
+  VARFMT(VT_R8,V_R8,8.0995,"#.##",S_OK,"8.1");
+  VARFMT(VT_R8,V_R8,0.0994,"#.##",S_OK,".1");
 
 
   /* 'out' is not cleared */

dlls/oleaut32/varformat.c

@@ -1285,12 +1285,21 @@ static HRESULT VARIANT_FormatNumber(LPVARIANT pVarIn, LPOLESTR lpszFormat,
         have_frac = -pad;
         pad = 0;
       }
+      if(exponent < 0 && exponent > (-256 + have_int + have_frac))
+      {
+        /* Remove exponent notation */
+        memmove(rgbDig - exponent, rgbDig, have_int + have_frac);
+        ZeroMemory(rgbDig, -exponent);
+        have_frac -= exponent;
+        exponent = 0;
+      }
     }
 
     /* Rounding the number */
     if (have_frac > need_frac)
     {
-      prgbDig = &rgbDig[have_int + need_frac];
+      prgbDig = &rgbDig[have_int + need_frac ? need_frac + 1 : 0];
+      if (*prgbDig < 5) prgbDig--;
       have_frac = need_frac;
       if (*prgbDig >= 5)
       {