fix(csharp/src/Drivers/Apache/Spark): correct precision/scale handlin…

…g with zeros in fractional portion (apache#2198)

Fixed two bugs
1. scale should be able to be the same as precision
2. when leading zeros in fractional portion and positive exponent, the
significant digits where not calculated correctly.

csharp/src/Drivers/Apache/Hive2/DecimalUtility.cs

@@ -45,7 +45,7 @@ internal static void GetBytes(string value, int precision, int scale, int byteWi
  {
  throw new ArgumentOutOfRangeException(nameof(precision), precision, "precision value must be greater than zero.");
  }
- if (scale < 0 || scale >= precision)
+ if (scale < 0 || scale > precision)
  {
  throw new ArgumentOutOfRangeException(nameof(scale), scale, "scale value must be in the range 0 .. precision.");
  }
@@ -165,8 +165,14 @@ private static void ProcessDecimal(ReadOnlySpan<char> value, int precision, int
  frac_length = Math.Max(Math.Min(frac_length - exponent, tempSignificant.Length - int_length), 0);
  }
  // Reset the integer and fractional span
- integerSpan = tempSignificant.Slice(0, int_length);
  fractionalSpan = tempSignificant.Slice(int_length, frac_length);
+ integerSpan = tempSignificant.Slice(0, int_length);
+ // Trim leading zeros fron new integer span
+ while (integerSpan.Length > 0 && integerSpan[0] == AsciiZero)
+ {
+ integerSpan = integerSpan.Slice(1);
+ int_length -= 1;
+ }
  }
 
  int neededPrecision = int_length + frac_length;

csharp/test/Drivers/Apache/Hive2/DecimalUtilityTests.cs

@@ -143,6 +143,11 @@ public static IEnumerable<object[]> Decimal128Data()
  yield return new object[] { "-0.1E0", 38, 3, 16, new byte[] { 156, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 }, new SqlDecimal(-0.1) };
  yield return new object[] { "-1e-1", 38, 3, 16, new byte[] { 156, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 }, new SqlDecimal(-0.1) };
  yield return new object[] { "-0.01e1", 38, 3, 16, new byte[] { 156, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 }, new SqlDecimal(-0.1) };
+
+ yield return new object[] { "0.99999999999999999999999999999999999999", 38, 38, 16, new byte[] { 255, 255, 255, 255, 63, 34, 138, 9, 122, 196, 134, 90, 168, 76, 59, 75 } };
+ yield return new object[] { "0.99999999999999999999999999999999999999E0", 38, 38, 16, new byte[] { 255, 255, 255, 255, 63, 34, 138, 9, 122, 196, 134, 90, 168, 76, 59, 75 } };
+ yield return new object[] { "9.99999999999999999999999999999999999990e-1", 38, 38, 16, new byte[] { 255, 255, 255, 255, 63, 34, 138, 9, 122, 196, 134, 90, 168, 76, 59, 75 } };
+ yield return new object[] { "0.0000000000000000000000000000000000000099999999999999999999999999999999999999e38", 38, 38, 16, new byte[] { 255, 255, 255, 255, 63, 34, 138, 9, 122, 196, 134, 90, 168, 76, 59, 75 } };
  }
 
  private static SqlDecimal GetSqlDecimal128(in byte[] valueBuffer, int index, int precision, int scale)