Validate inputs for safe logarithm calculation (#8439)

- Ensure both previousPoint and previousPoint2 are non-zero.
- Prevent division by zero and undefined errors.
- Add unit test to verity the new validation logic.

Indicators/AugenPriceSpike.cs

@@ -64,7 +64,7 @@ public AugenPriceSpike(string name, int period)
             }
             _standardDeviation = new StandardDeviation(period);
             _rollingData = new RollingWindow<decimal>(3);
-            WarmUpPeriod = period+2;
+            WarmUpPeriod = period + 2;
         }
 
         /// <summary>
@@ -91,9 +91,10 @@ protected override decimal ComputeNextValue(IndicatorDataPoint input)
             var previousPoint2 = _rollingData[2];
 
             var logPoint = 0.0;
-            if (previousPoint2 != 0)
+            // Ensure the logarithm operation is valid, as log(0) is undefined, and avoid division by zero.
+            if (previousPoint != 0 && previousPoint2 != 0)
             {
-                logPoint = Math.Log((double)(previousPoint / previousPoint2));
+                logPoint = Math.Log((double)previousPoint / (double)previousPoint2);
             }
 
             _standardDeviation.Update(input.Time, (decimal)logPoint);

Tests/Indicators/AugenPriceSpikeTests.cs

@@ -104,5 +104,26 @@ public override void ResetsProperly()
             aps.Reset();
             TestHelper.AssertIndicatorIsInDefaultState(aps);
         }
+
+        [Test]
+        public void DoesNotThrowOverflowException()
+        {
+            var aps = new AugenPriceSpike(5);
+            var values = new List<decimal>
+            {
+                decimal.MaxValue,
+                0,
+                1e-18m,
+                decimal.MaxValue,
+                1m
+            };
+
+            var date = new DateTime(2024, 12, 2, 12, 0, 0);
+
+            for (var i = 0; i < values.Count; i++)
+            {
+                Assert.DoesNotThrow(() => aps.Update(date, values[i]));
+            }
+        }
     }
 }