Fix add-in status consistency issue

When initializing an add-in dabatase ensure that all add-ins have all
their dependencies enabled. The database takes care to keep the
enabled status consistent at run-time (so if an add-in is disabled,
all dependent add-ins will also be disabled). However, that status
may already be inconsistent when loading the database, and that
may cause add-in loading issues. This may happen for example if
add-in A is disabled, and then an add-in B that depends on A is
installed externally, outside of the control of the db. With the
changes of this commit, when the db is initialized it will detect
that B depends on a disabled add-in and it will be disabled too.

Fixes VSTS #952473

3 files changed, 66 insertions, 15 deletions

diff --git a/Mono.Addins/Mono.Addins.Database/AddinDatabase.cs b/Mono.Addins/Mono.Addins.Database/AddinDatabase.cs
index 4dabf61..7d5a1d2 100644
--- a/Mono.Addins/Mono.Addins.Database/AddinDatabase.cs
+++ b/Mono.Addins/Mono.Addins.Database/AddinDatabase.cs
@@ -497,7 +497,7 @@ namespace Mono.Addins.Database
 				addinEngine.ActivateAddin (id);
 		}
 		
-		public void DisableAddin (string domain, string id, bool exactVersionMatch = false)
+		public void DisableAddin (string domain, string id, bool exactVersionMatch = false, bool onlyForCurrentSession = false)
 		{
 			Addin ai = GetInstalledAddin (domain, id, true);
 			if (ai == null)
@@ -505,8 +505,8 @@ namespace Mono.Addins.Database
 
 			if (!IsAddinEnabled (domain, id, exactVersionMatch))
 				return;
-			
-			Configuration.SetEnabled (id, false, ai.AddinInfo.EnabledByDefault, exactVersionMatch);
+
+			Configuration.SetEnabled (id, false, ai.AddinInfo.EnabledByDefault, exactVersionMatch, onlyForCurrentSession);
 			SaveConfiguration ();
 			
 			// Disable all add-ins which depend on it
@@ -531,7 +531,7 @@ namespace Mono.Addins.Database
 						Addin adepinfo = GetInstalledAddin (domain, adepid, false, true);
 						
 						if (adepinfo == null) {
-							DisableAddin (domain, ainfo.Id);
+							DisableAddin (domain, ainfo.Id, onlyForCurrentSession: onlyForCurrentSession);
 							break;
 						}
 					}
@@ -539,7 +539,7 @@ namespace Mono.Addins.Database
 			}
 			catch {
 				// If something goes wrong, enable the add-in again
-				Configuration.SetEnabled (id, true, ai.AddinInfo.EnabledByDefault, false);
+				Configuration.SetEnabled (id, true, ai.AddinInfo.EnabledByDefault, false, onlyForCurrentSession);
 				SaveConfiguration ();
 				throw;
 			}
@@ -547,7 +547,46 @@ namespace Mono.Addins.Database
 			if (addinEngine != null && addinEngine.IsInitialized)
 				addinEngine.UnloadAddin (id);
 		}
-		
+
+		public void UpdateEnabledStatus (string domain)
+		{
+			// Ensure that all enabled addins that have dependencies also have their dependencies enabled.
+			HashSet<Addin> updatedAddins = new HashSet<Addin> ();
+			var allAddins = GetInstalledAddins (domain, AddinSearchFlagsInternal.IncludeAddins | AddinSearchFlagsInternal.LatestVersionsOnly).ToList ();
+			foreach (Addin addin in allAddins)
+				UpdateEnabledStatus (domain, addin, allAddins, updatedAddins);
+		}
+
+		void UpdateEnabledStatus (string domain, Addin addin, List<Addin> allAddins, HashSet<Addin> updatedAddins)
+		{
+			if (!updatedAddins.Add (addin))
+				return;
+
+			if (!addin.Enabled)
+				return;
+
+			// Make sure all dependencies of this add-in have an up to date enabled status
+
+			foreach (Dependency dep in addin.AddinInfo.Dependencies) {
+				var adep = dep as AddinDependency;
+				if (adep == null)
+					continue;
+
+				string adepid = Addin.GetFullId (addin.AddinInfo.Namespace, adep.AddinId, null);
+				var dependency = allAddins.FirstOrDefault (a => Addin.GetFullId (a.Namespace, a.LocalId, null) == adepid);
+				if (dependency != null) {
+					UpdateEnabledStatus (domain, dependency, allAddins, updatedAddins);
+					if (!dependency.Enabled) {
+						// One of the dependencies is disabled, so this add-in also needs to be disabled.
+						// However, we disabled only for the current configuration, we don't want to change
+						// what the user configured.
+						DisableAddin (domain, addin.Id, onlyForCurrentSession: true);
+						return;
+					}
+				}
+			}
+		}
+
 		public void RegisterForUninstall (string domain, string id, IEnumerable<string> files)
 		{
 			DisableAddin (domain, id, true);
@@ -1955,6 +1994,7 @@ namespace Mono.Addins.Database
 	}
 	
 	// Keep in sync with AddinSearchFlags
+	[Flags]
 	enum AddinSearchFlagsInternal
 	{
 		IncludeAddins = 1,
diff --git a/Mono.Addins/Mono.Addins.Database/DatabaseConfiguration.cs b/Mono.Addins/Mono.Addins.Database/DatabaseConfiguration.cs
index 37779ec..14d8840 100644
--- a/Mono.Addins/Mono.Addins.Database/DatabaseConfiguration.cs
+++ b/Mono.Addins/Mono.Addins.Database/DatabaseConfiguration.cs
@@ -39,7 +39,7 @@ namespace Mono.Addins.Database
 	internal class DatabaseConfiguration
 	{
 		Dictionary<string,AddinStatus> addinStatus = new Dictionary<string,AddinStatus> ();
-		
+
 		internal class AddinStatus
 		{
 			public AddinStatus (string addinId)
@@ -48,11 +48,15 @@ namespace Mono.Addins.Database
 			}
 
 			public string AddinId;
-			public bool Enabled;
+			public bool ConfigEnabled;
+			public bool? SessionEnabled;
 			public bool Uninstalled;
 			public List<string> Files;
+			public bool Enabled {
+				get { return SessionEnabled ?? ConfigEnabled; }
+			}
 		}
-		
+
 		public bool IsEnabled (string addinId, bool defaultValue)
 		{
 			var addinName = Addin.GetIdName (addinId);
@@ -71,7 +75,7 @@ namespace Mono.Addins.Database
 				return defaultValue;
 		}
 		
-		public void SetEnabled (string addinId, bool enabled, bool defaultValue, bool exactVersionMatch)
+		public void SetEnabled (string addinId, bool enabled, bool defaultValue, bool exactVersionMatch, bool onlyForTheSession = false)
 		{
 			if (IsRegisteredForUninstall (addinId))
 				return;
@@ -83,11 +87,16 @@ namespace Mono.Addins.Database
 			
 			if (s == null)
 				s = addinStatus [addinName] = new AddinStatus (addinName);
-			s.Enabled = enabled;
+			if (onlyForTheSession)
+				s.SessionEnabled = enabled;
+			else {
+				s.ConfigEnabled = enabled;
+				s.SessionEnabled = null;
+			}
 
 			// If enabling a specific version of an add-in, make sure the add-in is enabled as a whole
 			if (enabled && exactVersionMatch)
-				SetEnabled (addinId, true, defaultValue, false);
+				SetEnabled (addinId, true, defaultValue, false, onlyForTheSession);
 		}
 		
 		public void RegisterForUninstall (string addinId, IEnumerable<string> files)
@@ -96,7 +105,7 @@ namespace Mono.Addins.Database
 			if (!addinStatus.TryGetValue (addinId, out s))
 				s = addinStatus [addinId] = new AddinStatus (addinId);
 			
-			s.Enabled = false;
+			s.ConfigEnabled = false;
 			s.Uninstalled = true;
 			s.Files = new List<string> (files);
 		}
@@ -171,7 +180,7 @@ namespace Mono.Addins.Database
 				foreach (XmlElement elem in statusElem.SelectNodes ("Addin")) {
 					AddinStatus status = new AddinStatus (elem.GetAttribute ("id"));
 					string senabled = elem.GetAttribute ("enabled");
-					status.Enabled = senabled.Length == 0 || senabled == "True";
+					status.ConfigEnabled = senabled.Length == 0 || senabled == "True";
 					status.Uninstalled = elem.GetAttribute ("uninstalled") == "True";
 					config.addinStatus [status.AddinId] = status;
 					foreach (XmlElement fileElem in elem.SelectNodes ("File")) {
@@ -196,7 +205,7 @@ namespace Mono.Addins.Database
 				foreach (AddinStatus e in addinStatus.Values) {
 					tw.WriteStartElement ("Addin");
 					tw.WriteAttributeString ("id", e.AddinId);
-					tw.WriteAttributeString ("enabled", e.Enabled.ToString ());
+					tw.WriteAttributeString ("enabled", e.ConfigEnabled.ToString ());
 					if (e.Uninstalled)
 						tw.WriteAttributeString ("uninstalled", "True");
 					if (e.Files != null && e.Files.Count > 0) {
diff --git a/Mono.Addins/Mono.Addins/AddinRegistry.cs b/Mono.Addins/Mono.Addins/AddinRegistry.cs
index f51b4db..1efeb1c 100644
--- a/Mono.Addins/Mono.Addins/AddinRegistry.cs
+++ b/Mono.Addins/Mono.Addins/AddinRegistry.cs
@@ -220,6 +220,8 @@ namespace Mono.Addins
 				currentDomain = database.GetFolderDomain (null, this.startupDirectory);
 			} else
 				currentDomain = AddinDatabase.GlobalDomain;
+
+			database.UpdateEnabledStatus (currentDomain);
 		}
 
 		/// <summary>