`Counter` never incremented in an `do-while` loop — infinite loop risk (`HVACVariableRefrigerantFlow.cc`)

[dareumnam]

Issue overview

In HVACVariableRefrigerantFlow.cc, the do-while loop to calculate Ncomp has a max iteration guard Counter >= 30, but Counter is initialized to 1 and never incremented inside the loop here.
The adjacent similar block already does this correctly with Counter = Counter + 1, this block is just missing the same line.
This also fixes a CppCheck knownConditionTrueFalse warning at HVACVariableRefrigerantFlow.cc:11383, where Counter >= 30 is flagged as always false.

Operating System (Multiple choices)

Windows

Operating System Version

11

Version of EnergyPlus

26.1.0

Unmethours link or helpdesk ticket number

N/A

Defect file

No response

[rraustad]

Oh, that's good. It means it's always converging on it's own in our test files. You could use

|| (Counter++ >= 30)

[dareumnam]

Thanks so much for the suggestion @rraustad.
After thinking it through, I'd prefer to keep ++Counter; as a separate line. The reason is that placing Counter++ inside the condition relies on short-circuit evaluation. When the first condition is true (converged), Counter++ never gets executed, meaning Counter won't actually increment. (please correct me if I'm wrong.)
While this doesn't affect correctness since the loop exits anyway, it makes the behavior of Counter subtly dependent on whether convergence happens, which could be a bit confusing to reason about. Having ++Counter; on its own line makes the loop control unconditional and easier to follow. Hope that makes sense!

[rraustad]

@dareumnam there is always more than 1 way to fix things. I was just looking over this issue and suggesting that a new line was not needed. You are correct in your evaluation but if the first part of the conditional is true then it does not matter what happens to Counter because the while loop ends. Counter is only required to increment if the loop continues. You can fix this any way you choose and a new line will work just fine.

[dareumnam]

That makes sense, and you had already considered this. If either way works, I'll go with the option that doesn't add more lines. Thanks so much for your input! @rraustad