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Fix floating-point precision error in calculator #4555

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Fix floating-point precision error in calculator #4555

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1ee38cc
Fix floating-point precision error in calculator
Jul 1, 2026
330b93a
Preserve integer precision in calculator
Jul 1, 2026
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6 changes: 5 additions & 1 deletion Flow.Launcher.Test/Plugins/CalculatorTest.cs
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Original file line number Diff line number Diff line change
@@ -1,4 +1,4 @@
using System;
using System;
using System.Collections.Generic;
using System.Reflection;
using Flow.Launcher.Plugin.Calculator;
Expand Down Expand Up @@ -114,6 +114,10 @@ public void ThousandsSeparatorTest_LargeNumber()
[TestCase(@"sqrt(-1)", "")]
[TestCase(@"log(0)", "")]
[TestCase(@"invalid_expression", "")]
// Floating point precision
[TestCase(@"3000000-2911111.82", "88888.18")]
[TestCase(@"123456789012345", "123456789012345")]
[TestCase(@"9007199254740991", "9007199254740991")]
public void CalculatorTest(string expression, string result)
{
_settings.UseThousandsSeparator = false;
Expand Down
16 changes: 13 additions & 3 deletions Plugins/Flow.Launcher.Plugin.Calculator/Main.cs
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Original file line number Diff line number Diff line change
@@ -1,4 +1,4 @@
using System;
using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
Expand Down Expand Up @@ -128,7 +128,18 @@ public List<Result> Query(Query query)

if (!string.IsNullOrEmpty(result.ToString()))
{
decimal roundedResult = Math.Round(Convert.ToDecimal(result), _settings.MaxDecimalPlaces, MidpointRounding.AwayFromZero);
double rawValue = Convert.ToDouble(result);
decimal decValue;
if (double.IsNaN(rawValue) || double.IsInfinity(rawValue))
{
decValue = (decimal)rawValue;
}
Comment on lines +133 to +136

@cubic-dev-ai cubic-dev-ai Bot Jul 1, 2026

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P2: The explicit NaN/Infinity branch casts special double values to decimal, which throws an OverflowException instead of handling them. decimal has no representation for NaN or Infinity, so this check gives a false impression of handling while guaranteeing a throw.

Prompt for AI agents 
Check if this issue is valid — if so, understand the root cause and fix it. At Plugins/Flow.Launcher.Plugin.Calculator/Main.cs, line 133:

<comment>The explicit NaN/Infinity branch casts special double values to `decimal`, which throws an `OverflowException` instead of handling them. `decimal` has no representation for `NaN` or `Infinity`, so this check gives a false impression of handling while guaranteeing a throw.</comment>

<file context>
@@ -130,13 +130,14 @@ public List<Result> Query(Query query)
                     double rawValue = Convert.ToDouble(result);
                     decimal decValue;
-                    try
+                    if (double.IsNaN(rawValue) || double.IsInfinity(rawValue))
                     {
-                        decValue = decimal.Parse(rawValue.ToString("G14", CultureInfo.InvariantCulture), NumberStyles.Any, CultureInfo.InvariantCulture);
</file context>
Suggested change
if (double.IsNaN(rawValue) || double.IsInfinity(rawValue))
{
decValue = (decimal)rawValue;
}
if (double.IsNaN(rawValue) || double.IsInfinity(rawValue))
{
return new List<Result>
{
new Result
{
Title = rawValue.ToString(CultureInfo.InvariantCulture),
IcoPath = IcoPath,
Score = 300
}
};
}

else
{
string format = (rawValue % 1 == 0) ? "G17" : "G14";
decValue = decimal.Parse(rawValue.ToString(format, CultureInfo.InvariantCulture), NumberStyles.Any, CultureInfo.InvariantCulture);
}
decimal roundedResult = Math.Round(decValue, _settings.MaxDecimalPlaces, MidpointRounding.AwayFromZero);
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coderabbitai[bot] marked this conversation as resolved.
string newResult = FormatResult(roundedResult);

return
Expand All @@ -138,7 +149,6 @@ public List<Result> Query(Query query)
Title = newResult,
IcoPath = IcoPath,
Score = 300,
// Check context nullability for unit testing
SubTitle = Context == null ? string.Empty : Localize.flowlauncher_plugin_calculator_copy_number_to_clipboard(),
CopyText = newResult,
Action = c =>
Expand Down