(chocolatey#3292) Ensure pre-release flag is used for parent lookup

These changes makes sure that we pass along any pre-release flag
when there is a pre-release package that is a parent of one of the
packages that we are installing, and to verify that the results is not
null before we attempt to use it.

This ensures that pre-release only packages can be found when we
look up the parent, and if by some reason the package can not be
found we do not throw an undesired null exception in this case.

src/chocolatey/infrastructure.app/services/NugetService.cs

@@ -1234,8 +1234,21 @@ public virtual ConcurrentDictionary<string, PackageResult> Upgrade(ChocolateyCon
                                 }
                             }
 
+                            var configPrerelease = config.Prerelease;
+                            config.Prerelease = parentPackage.Version.IsPrerelease;
+
                             var availablePackageDependency = NugetList.FindPackage(parentPackage.Id, config, _nugetLogger, sourceCacheContext, remoteEndpoints);
-                            NugetCommon.GetPackageDependencies(availablePackageDependency.Identity, NuGetFramework.AnyFramework, sourceCacheContext, _nugetLogger, remoteEndpoints, sourcePackageDependencyInfos, sourceDependencyCache, config).GetAwaiter().GetResult();
+
+                            config.Prerelease = configPrerelease;
+
+                            if (availablePackageDependency != null)
+                            {
+                                NugetCommon.GetPackageDependencies(availablePackageDependency.Identity, NuGetFramework.AnyFramework, sourceCacheContext, _nugetLogger, remoteEndpoints, sourcePackageDependencyInfos, sourceDependencyCache, config).GetAwaiter().GetResult();
+                            }
+                            else
+                            {
+                                this.Log().Warn("Unable to find the parent package '{0}'.", parentPackage.Id);
+                            }
                         }
 
                         var removedSources = RemovePinnedSourceDependencies(sourcePackageDependencyInfos, allLocalPackages);

tests/chocolatey-tests/commands/choco-upgrade.Tests.ps1

@@ -548,6 +548,33 @@ To upgrade a local, or remote file, you may use:
         }
     }
 
+    Context 'Upgrading a package where parent only contain pre-releases' -Tag Testing {
+        BeforeAll {
+            Restore-ChocolateyInstallSnapshot
+
+            $null = Invoke-Choco install isdependency --version 1.0.0
+            $null = Invoke-Choco install hasstabledependency
+
+            $Output = Invoke-Choco upgrade isdependency --version 2.0.0
+        }
+
+        It "Should exit with sucess (0)" {
+            $Output.ExitCode | Should -Be 0 -Because $Output.String
+        }
+
+        It "Should report successful upgrade" {
+            $Output.Lines | Should -Contain "isdependency v2.0.0" -Because $Output.String
+            $Output.Lines | Should -Contain "Chocolatey upgraded 1/1 packages." -Because $Output.String
+        }
+
+        It "Should have upgraded the correct files" {
+            $ExpectedFile = "${env:ChocolateyInstall}/lib/isdependency/isdependency"
+            "$ExpectedFile.nupkg" | Should -Exist
+            $NuspecContent = [xml](Get-Content "$ExpectedFile.nuspec")
+            $NuspecContent.package.metadata.version | Should -Be "2.0.0"
+        }
+    }
+
     # This needs to be (almost) the last test in this block, to ensure NuGet configurations aren't being created.
     # Any tests after this block are expected to generate the configuration as they're explicitly using the NuGet CLI
     Test-NuGetPaths