Fixed restore from CLI when packages need to be updated

src/NuGetForUnity/Editor/NugetPackageInstaller.cs

@@ -118,7 +118,7 @@ private static PackageInstallOperationResult Install(
                         installedPackage.Version,
                         package.Version,
                         package.Version);
-                    return NugetPackageUpdater.UpdateWithInformation(installedPackage, package, refreshAssets);
+                    return NugetPackageUpdater.UpdateWithInformation(installedPackage, package, refreshAssets, isSlimRestoreInstall);
                 }
 
                 if (comparisonResult > 0)
@@ -131,7 +131,7 @@ private static PackageInstallOperationResult Install(
                             installedPackage.Id,
                             installedPackage.Version,
                             package.Version);
-                        return NugetPackageUpdater.UpdateWithInformation(installedPackage, package, refreshAssets);
+                        return NugetPackageUpdater.UpdateWithInformation(installedPackage, package, refreshAssets, isSlimRestoreInstall);
                     }
 
                     NugetLogger.LogVerbose(

src/NuGetForUnity/Editor/NugetPackageUninstaller.cs

@@ -20,11 +20,12 @@ public static class NugetPackageUninstaller
         /// <param name="package">The NugetPackage to uninstall.</param>
         /// <param name="uninstallReason">The reason uninstall is being called.</param>
         /// <param name="refreshAssets">True to force Unity to refresh its Assets folder.  False to temporarily ignore the change.  Defaults to true.</param>
-        public static void Uninstall([NotNull] INugetPackageIdentifier package, PackageUninstallReason uninstallReason, bool refreshAssets = true)
+        /// <param name="isSlimRestore">True if uninstall needs to be done as part of slim restore operation.</param>
+        public static void Uninstall([NotNull] INugetPackageIdentifier package, PackageUninstallReason uninstallReason, bool refreshAssets = true, bool isSlimRestore = false)
         {
             // Checking for pre-imported packages also ensures that the pre-imported package list is up-to-date before we uninstall packages.
             // Without this the pre-imported package list can contain the package as we delete the .dll before we call 'AssetDatabase.Refresh()'.
-            if (UnityPreImportedLibraryResolver.IsAlreadyImportedInEngine(package.Id, false))
+            if (!isSlimRestore && UnityPreImportedLibraryResolver.IsAlreadyImportedInEngine(package.Id, false))
             {
                 Debug.LogWarning($"Uninstalling {package} makes no sense because it is a package that is 'pre-imported' by Unity.");
             }
@@ -44,7 +45,7 @@ public static void Uninstall([NotNull] INugetPackageIdentifier package, PackageU
             PackageContentManager.DeletePackageContentPackage(foundPackage);
 
             // Since uninstall all will remove all packages we don't have to handle dependencies here.
-            if (uninstallReason != PackageUninstallReason.UninstallAll)
+            if (uninstallReason != PackageUninstallReason.UninstallAll && !isSlimRestore)
             {
                 // uninstall all non manually installed dependencies that are not a dependency of another installed package
                 var frameworkDependencies = foundPackage.CurrentFrameworkDependencies;

src/NuGetForUnity/Editor/NugetPackageUpdater.cs

@@ -27,7 +27,7 @@ public static bool Update(
             bool refreshAssets = true,
             PackageUninstallReason uninstallReason = PackageUninstallReason.IndividualUpdate)
         {
-            var result = UpdateWithInformation(currentVersion, newVersion, refreshAssets, uninstallReason);
+            var result = UpdateWithInformation(currentVersion, newVersion, refreshAssets, false, uninstallReason);
             return result.Successful;
         }
 
@@ -73,18 +73,20 @@ public static void UpdateAll(
         /// <param name="currentVersion">The current package to uninstall.</param>
         /// <param name="newVersion">The package to install.</param>
         /// <param name="refreshAssets">True to refresh the assets inside Unity. False to ignore them (for now). Defaults to true.</param>
+        /// <param name="isSlimRestoreInstall">True if update needs to be done as part of slim restore operation.</param>
         /// <param name="uninstallReason">The reason uninstall is being called.</param>
         /// <returns>The information about how the package has been installed.</returns>
         internal static PackageInstallOperationResult UpdateWithInformation(
             [NotNull] INugetPackageIdentifier currentVersion,
             [NotNull] INugetPackage newVersion,
             bool refreshAssets = true,
+            bool isSlimRestoreInstall = false,
             PackageUninstallReason uninstallReason = PackageUninstallReason.IndividualUpdate)
         {
             NugetLogger.LogVerbose("Updating {0} {1} to {2}", currentVersion.Id, currentVersion.Version, newVersion.Version);
-            NugetPackageUninstaller.Uninstall(currentVersion, uninstallReason, false);
+            NugetPackageUninstaller.Uninstall(currentVersion, uninstallReason, false, isSlimRestoreInstall);
             newVersion.IsManuallyInstalled = newVersion.IsManuallyInstalled || currentVersion.IsManuallyInstalled;
-            return NugetPackageInstaller.Install(newVersion, refreshAssets);
+            return NugetPackageInstaller.Install(newVersion, refreshAssets, isSlimRestoreInstall);
         }
     }
 }