[Run][Calculator plugin] Wrong result when there are lots of decimal places

[prime167]

ℹ Computer information

• PowerToys version: 0.29.3
• PowerToy Utility: Run
• Running PowerToys as Admin: Yes
• Windows build number: 20H2 19042.746

📝 Provide detailed reproduction steps (if any)

1. Press Alt+Space to open search box
2. Enter 89/58.36, you can get answer 1.5250171350
3. Continue to append 6
4. When the input is 89/58.366666666666666666 (and more 6) the result becomes totally wrong

✔️ Expected result

1.5248429469

❌ Actual result

29.4075426386
75.3113975135
1187.3728567606
...

📷 Screenshots

[crutkas]

betting this is some type of mage issue with string to datatype. i don't know how much we'll be able to do here as we are string in, data out.

[htcfreek]

betting this is some type of mage issue with string to datatype. i don't know how much we'll be able to do here as we are string in, data out.

@crutkas
This is not correct. We do conversation from double to decimal. But I think you are correct that the overflow cause is within mages or better said that mages uses double instead of decimal. (Decimal is more precise.)

I can check if this can be configured in mages.

[crutkas]

What line? If I remember correctly we pass in a string to their engine. Data types is up to them

[htcfreek]

What line? If I remember correctly we pass in a string to their engine. Data types is up to them

PowerToys/src/modules/launcher/Plugins/Microsoft.PowerToys.Run.Plugin.Calculator/CalculateEngine.cs

Line 56 in 368c775

var decimalResult = Convert.ToDecimal(result, cultureInfo);

The problem is that we can't tell mages to use decimal. But we could check if the rounding code in our class works correct.

Btw. I can reproduce a overflow in the plugin that makes number incorrect. If you input for example =0.5555555555 and much more decimal digits after the point there will be some point where the result becomes different to the input.

And please have in mind that there is a PR awaiting review that fixes many bugs in the calc plugin: #18159

[htcfreek]

/dup #18574

[ghost]

Hi! We've identified this issue as a duplicate of another one that already exists on this Issue Tracker. This specific instance is being closed in favor of tracking the concern over on the referenced thread. Thanks for your report!

[ghost]

Hi! We've identified this issue as a duplicate of another one that already exists on this Issue Tracker. This specific instance is being closed in favor of tracking the concern over on the referenced thread. Thanks for your report!