Created attachment 214930 [details]
Minimum set of accounts showing the bug

When creating a budget report, in case there is an account with different currency than the parent account, the value is not converted in the commodity of the parent account before adding it, but simply added.

The Actuals are correctly calculated, though.

Example:
Parent account: Current Assets (HUF)
Sub account: Cash in Wallet with 10,000 HUF
Sub account: Test EUR with 100 EUR

Exchange rate is set so that 1 EUR = 300 HUF

When issuing a Budget Report, gives the following:
Actuals (correct)
Parent account: Current Assets with 40,000 HUF
Sub account: Cash in Wallet with 10,000 HUF
Sub account: Test EUR with 100 EUR

Budget (wrong)
Parent account: Current Assets with 10,100 HUF
Sub account: Current Assets with 10,000 HUF
Sub account: Test EUR with 100 EUR

I attach the example files.