[Bug 54456] New: vbscript memory leak in For Each with SafeArray as group

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=54456

Bug ID: 54456
           Summary: vbscript memory leak in For Each with SafeArray as
                    group
           Product: Wine
           Version: 7.21
          Hardware: x86-64
                OS: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: vbscript
          Assignee: [e-mail]
          Reporter: [e-mail]
      Distribution: ---

While porting Visual Pinball to cross platform, I started using XCode
Instruments to find some outstanding memory leaks.

Given the following code:

Class cvpmDictionary
   Private mDict
   Private Sub Class_Initialize : Set mDict =
CreateObject("Scripting.Dictionary") : mDict("key") = "value" : End Sub
   Public Function Keys         : Keys      = mDict.Keys           : End
Function
  End Class

Dim vpDict
  Set vpDict = New cvpmDictionary

Sub RollingTimer_Timer
    For Each obj In vpDict.Keys : Debug.Print "Key" : Next
  End Sub

RollingTimer_Timer gets executed a few times a second. This seems to leak the
vpDict.Keys SafeArray.

If I change the code to:

Sub RollingTimer_Timer
    Dim x
    x = vpDict.Keys
    For Each obj In x : Debug.Print "Key" : Next
  End Sub

No memory leaks are detected. In this case, release_exec calls VariantClear for
ctx->vars which frees the SafeArray in X.

In the first case, vpDict.Keys doesn't appear to be stored anywhere, so nothing
is freed in release_exec.