No IntelliSense in lambda body of ternary consequent expression when ternary alternative expression is missing or invalid

[just-ero]

Full issue information + repro project:
https://github.com/just-ero/roslyn-issues-repros/tree/main/5.0.0/005_NoIntelliSense_FuncTernary

Version

Note

Roslyn: 5.0.0-1.25361.2 (fdd628a)
.NET SDK: 10.0.100-preview.6.25358.103

Visual Studio Code: 1.102.1
C# Extension: 2.86.19
C# Dev Kit Extension: 1.40.25

Steps to Reproduce

1. Add the following code wherever syntactically applicable:

   void M()
   {
       Func<int, string> f = true
           ? (i => i.ToString())
           : (i => );
   }

   Note: Any invalid alternative expression results in the behavior.
2. Hover over i.ToString() to see no IntelliSense.

Expected Behavior

The consequent expression is correctly recognized, IntelliSense is offered, and code has semantic highlighting.

Actual Behavior

It does not.

[CyrusNajmabadi]

@333fred The parse trees are well formed here. So it's not an issue with that. My guess is that one or both sides of conditional cannot be bound due to errors (when binding each branch against the other). And in that case, we don't attempt to then rebind using the target type.

My hope is that this is straightforward binding error recovery in teh compiler.

I'm making this unassigned. @jaredpar to triage for compiler.