[#3958] fix key command action handler gets deleted by content assist

[ghentschke]

fixes #3958 by handling multiple calls on assistSessionStarted(ContentAssistEvent)

[ghentschke]

@mickaelistria can you please take a look at this?

[github-actions]

Test Results

   852 files  ±0     852 suites  ±0   52m 59s ⏱️ - 4m 59s
 7 940 tests ±0   7 697 ✅ ±0  243 💤 ±0  0 ❌ ±0 
20 322 runs  ±0  19 667 ✅ ±0  655 💤 ±0  0 ❌ ±0 

Results for commit 46f8d62. ± Comparison against base commit 4888468.

[mickaelistria]

I think this patch is good and is the simplest way to address the reported issue.
Sure, one could argue that this method should not be called multiple times, but anyway, there is no real way to prevent a method from being called multiple times, so making it multiple-calls-able seems more robust that working on the caller to call it only once.

[merks]

It looks fine to me as well. Evidently assistSessionEnded is already guarded for being called multiple times or for being called without assistSessionStarted having been called, so guarding multiple calls to assistSessionEnded without a subsequent call to assistSessionEnded seems safe enough.

[ghentschke]

Thank for your fast replies @mickaelistria and @merks
IMO it would be great if we can merge this soon, as it the editor behavior is quite annoying for users.
Can it be part of 2026-06 or is it too late?