oleaut32: Strip trailing decimal zeroes when rounding a number in VarFormat.

dlls/oleaut32/tests/varformat.c

@@ -380,6 +380,7 @@ static void test_VarFormat(void)
   VARFMT(VT_R8,V_R8,-1.57,"#.##",S_OK,"-1.57");
   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");
 
 
   /* 'out' is not cleared */

dlls/oleaut32/varformat.c

@@ -1313,6 +1313,9 @@ static HRESULT VARIANT_FormatNumber(LPVARIANT pVarIn, LPOLESTR lpszFormat,
         }
         else
           (*prgbDig)++;
+        /* We converted trailing digits to zeroes => have_frac has changed */
+        while (have_frac > 0 && rgbDig[have_int + have_frac - 1] == 0)
+          have_frac--;
       }
     }
     TRACE("have_int=%d,need_int=%d,have_frac=%d,need_frac=%d,pad=%d,exp=%d\n",