Fix BigDecimal precision when converting to double and integer. (#608)

Issue 98013

Author: gusbro

common/src/main/java/com/genexus/DecimalUtil.java

@@ -61,15 +61,18 @@ public static java.math.BigDecimal doubleToDec(double d, int len, int dec)
 		return new java.math.BigDecimal(CommonUtil.ltrim(CommonUtil.str(d, len, dec)));
 	}
 
+	private static final int DOUBLE_SCALE = 18; // ~17 decimal digits of precision for double
 	public static double decToDouble(java.math.BigDecimal decimal)
 	{
-		return decimal.doubleValue();
+		if(decimal.scale() >= DOUBLE_SCALE)
+			return decimal.setScale(DOUBLE_SCALE, BigDecimal.ROUND_HALF_DOWN).doubleValue();
+		else return decimal.doubleValue();
 	}
 
  	public static BigDecimal unexponentString(String num) 
    	{
 		num = num.trim();
-		
+
    		String exponent;
    		int scaleAdj = 0;
    		int epos = num.indexOf('E');

common/src/main/java/com/genexus/util/ExpressionEvaluator.java

@@ -735,7 +735,7 @@ public static EvalValue multiply(EvalValue a, EvalValue b)
 	public static EvalValue divide(EvalValue a, EvalValue b)
 	{
 		if (a.stringValue == null)
-			return new EvalValue(a.getDecimal().divide(b.getDecimal(), MathContext.DECIMAL64));
+			return new EvalValue(a.getDecimal().divide(b.getDecimal(), MathContext.DECIMAL128));
 		else
 			throw new IllegalArgumentException("Invalid operation: string / string");
 	}