Disable all obsolete files that are referenced by packages.

Previously, the Version Handler would only disable a file if
it was determined as obsolete on a file-by-file basis.
For example, a/b/c/foo-1.2.3.dll is older than a/b/c/foo-1.2.4.dll
so a/b/c/foo-1.2.3.dll would be disabled and marked for deletion.

However, if a file was obsolete *and* moved between package updates
it would not be disabled but would be marked for deletion as the
file would not exist in the most recent package manifest. This
scenario is problematic if the developer doesn't clean up the old
file when prompted (target builds break) or the file is loaded in
the editor (editor plugins break).

This change adds files that are determined obsolete by
comparing differences between package manifests to the set of
files to disable.

Bug: 150886091
Change-Id: I49c711feef9817c79e9d36ffebc4f8503fba33ed

Author: Stewart Miles

source/VersionHandlerImpl/src/VersionHandlerImpl.cs

@@ -919,6 +919,17 @@ public void Add(FileMetadata metadata) {
         /// <returns>true if any plugin metadata was modified and requires an
         /// AssetDatabase.Refresh(), false otherwise.</return>
         public bool EnableMostRecentPlugins() {
+            return EnableMostRecentPlugins(new HashSet<string>());
+        }
+
+        /// <summary>
+        /// If this instance references a set of plugins, enable the most
+        /// recent versions.
+        /// </summary>
+        /// <param name="disableFiles">Set of files in the project that should be disabled.</param>
+        /// <returns>true if any plugin metadata was modified and requires an
+        /// AssetDatabase.Refresh(), false otherwise.</return>
+        public bool EnableMostRecentPlugins(HashSet<string> disableFiles) {
             bool modified = false;
             int versionIndex = 0;
             int numberOfVersions = metadataByVersion.Count;
@@ -970,13 +981,16 @@ public bool EnableMostRecentPlugins() {
                 bool modifiedThisVersion = false;
                 // Only enable the most recent plugin - SortedDictionary
                 // orders keys in ascending order.
-                bool obsoleteVersion = (numberOfVersions > 1 &&
-                                        versionIndex < numberOfVersions);
+                bool obsoleteVersion =
+                    (numberOfVersions > 1 && versionIndex < numberOfVersions) ||
+                    disableFiles.Contains(metadata.filename);
                 // If this is an obsolete version.
                 if (obsoleteVersion) {
                     // Disable for all platforms and the editor.
                     editorEnabled = false;
                     selectedTargets = new HashSet<BuildTarget>();
+                    Log(String.Format("{0} is obsolete and will be disabled.", metadata.filename),
+                        verbose: true);
                 } else {
                     if (hasDotNetTargets) {
                         // Determine whether this is supported by the selected .NET version.
@@ -1055,6 +1069,8 @@ public bool EnableMostRecentPlugins() {
                 // Therefore, force a reimport of each file touched by the
                 // plugin importer.
                 if (modifiedThisVersion) {
+                    Log(String.Format("Metadata changed: force import of {0}", metadata.filename),
+                        verbose: true);
                     AssetDatabase.ImportAsset(metadata.filename,
                                               ImportAssetOptions.ForceUpdate);
                 }
@@ -1396,6 +1412,21 @@ public void ConsolidateManifests() {
         /// <returns>true if any plugin metadata was modified and requires an
         /// AssetDatabase.Refresh(), false otherwise.</return>
         public bool EnableMostRecentPlugins(bool forceUpdate) {
+            return EnableMostRecentPlugins(forceUpdate, new HashSet<string>());
+        }
+
+        /// <summary>
+        /// For each plugin (DLL) referenced by this set, disable targeting
+        /// for all versions and re-enable platform targeting for the most
+        /// recent version.
+        /// </summary>
+        /// <param name="forceUpdate">Whether the update was forced by the
+        /// user.</param>
+        /// <param name="disableFiles">Set of files that should be disabled.</param>
+        /// <returns>true if any plugin metadata was modified and requires an
+        /// AssetDatabase.Refresh(), false otherwise.</return>
+        public bool EnableMostRecentPlugins(bool forceUpdate,
+                                            HashSet<string> disableFiles) {
             bool modified = false;
 
             // If PluginImporter isn't available it's not possible
@@ -1474,7 +1505,7 @@ public bool EnableMostRecentPlugins(bool forceUpdate) {
             }
 
             foreach (var metadataByVersion in Values) {
-                modified |= metadataByVersion.EnableMostRecentPlugins();
+                modified |= metadataByVersion.EnableMostRecentPlugins(disableFiles);
             }
             return modified;
         }
@@ -1790,6 +1821,18 @@ public class ObsoleteFiles {
         /// </summary>
         public Dictionary<string, List<string>> referencedExcludingManifests;
 
+        /// <summary>
+        /// Get all referenced and unreferenced obsolete files.
+        /// </summary>
+        public HashSet<string> All {
+            get {
+                var all = new HashSet<string>();
+                all.UnionWith(unreferenced);
+                all.UnionWith(referenced.Keys);
+                return all;
+            }
+        }
+
         /// <summary>
         /// Build an ObsoleteFiles instance searching a set of
         /// ManifestReferences and a FileMetadataSet for old files.
@@ -2401,15 +2444,15 @@ public static void UpdateVersionedAssets(bool forceUpdate, Action complete) {
         if (!forceUpdate) {
             metadataSet = FileMetadataSet.FindWithPendingUpdates(metadataSet);
         }
-        if (metadataSet.EnableMostRecentPlugins(forceUpdate)) {
+
+        var obsoleteFiles = new ObsoleteFiles(
+            ManifestReferences.FindAndReadManifests(metadataSet), metadataSet);
+        if (metadataSet.EnableMostRecentPlugins(forceUpdate, obsoleteFiles.All)) {
             analytics.Report("enablemostrecentplugins", "Enable Most Recent Plugins");
             AssetDatabase.Refresh();
             Refreshing = true;
         }
 
-        var obsoleteFiles = new ObsoleteFiles(
-            ManifestReferences.FindAndReadManifests(metadataSet), metadataSet);
-
         // Obsolete files that are no longer referenced can be safely deleted, prompt the user for
         // confirmation if they have the option enabled.
         var cleanupFiles = new List<KeyValuePair<string, string>>();