[automated] Merge branch 'main' => 'release/dev18.0' (#18458)

* Fix a copypaste checking bug in unpickling (#18430)

* Tooltips: fix `null` annotation highlighting (#18457)

* Tooltips: fix `null` annotation highlighting

* Release notes

---------

Co-authored-by: Petr <psfinaki@users.noreply.github.com>
Co-authored-by: Eugene Auduchinok <eugene.auduchinok@gmail.com>

Author: 3 people

docs/release-notes/.FSharp.Compiler.Service/9.0.300.md

@@ -20,8 +20,10 @@
 * Fix duplicate parse error reporting for GetBackgroundCheckResultsForFileInProject ([Issue #18379](https://github.com/dotnet/fsharp/issues/18379) [PR #18380](https://github.com/dotnet/fsharp/pull/18380))
 * Fix MethodDefNotFound when compiling code invoking delegate with option parameter ([Issue #5171](https://github.com/dotnet/fsharp/issues/5171), [PR #18385](https://github.com/dotnet/fsharp/pull/18385))
 * Fix #r nuget ..." downloads unneeded packages ([Issue #18231](https://github.com/dotnet/fsharp/issues/18231), [PR #18393](https://github.com/dotnet/fsharp/pull/18393))
+* Fix checking bug in unpickling [PR #18430](https://github.com/dotnet/fsharp/pull/18430)
 * Reenable β-reduction and subsequent reoptimization of immediately-invoked F#-defined generic delegates. ([PR #18401](https://github.com/dotnet/fsharp/pull/18401))
 * Fixed [#18433](https://github.com/dotnet/fsharp/issues/18433), a rare case of an internal error in xml comment processing. ([PR #18436](https://github.com/dotnet/fsharp/pull/18436))
+* Fix missing `null` highlighting in tooltips ([PR #18457](https://github.com/dotnet/fsharp/pull/18457))
 
 ### Added
 * Added missing type constraints in FCS. ([PR #18241](https://github.com/dotnet/fsharp/pull/18241))

src/Compiler/Checking/NicePrint.fs

@@ -944,7 +944,7 @@ module PrintTypes =
         // Show nullness annotations unless explicitly turned off
         if denv.showNullnessAnnotations <> Some false then
             match nullness.Evaluate() with
-            | NullnessInfo.WithNull -> part2 ^^ wordL (tagText "| null")
+            | NullnessInfo.WithNull -> part2 ^^ wordL (tagPunctuation "|") ^^ wordL (tagKeyword "null") 
             | NullnessInfo.WithoutNull -> part2
             | NullnessInfo.AmbivalentToNull -> part2 //^^ wordL (tagText "__maybenull")
         else

src/Compiler/TypedTree/TypedTreePickle.fs

@@ -1122,7 +1122,7 @@ let unpickleObjWithDanglingCcus
 
         let res = u st1
         check viewedScope st1.ientities
-        check viewedScope st1.ientities
+        check viewedScope st1.ianoninfos
         check viewedScope st1.ivals
         check viewedScope st1.itypars
         res