1159 relax constraints when installing bundles

I think this is the right approach, but there are still a couple of issues:

1. If a bundle is installed like "tap image install 'DMM:2.1.2,DMM API:2.1.3'", the DMM API request is ignored. The image should fail to resolve, but will instead resolve to something the user did not ask for
2. If a bundle has a dependency on OpenTAP, the current OpenTAP installation might be downgraded, even if `--merge` is specified
3. If a new bundle member is added, downgrading to an older version will uninstall the new bundle member

These are a couple of strange behaviors I can think of off the top of my head. We should resolve these issues before merging this

Closes #1159

Engine/ThreadManager.cs

@@ -693,10 +693,7 @@ void processQueue()
         }
 
         private static TraceSource _log;
-        private static TraceSource log
-        {
-            get => (_log ?? (_log = Log.CreateSource("thread")));
-        }
+        private static TraceSource log => _log ??= Log.CreateSource("thread");
 
         /// <summary> Disposes the ThreadManager. This can optionally be done at program exit.</summary>
         public void Dispose()

Package/Image/ImageSpecifier.cs

@@ -113,6 +113,15 @@ public ImageIdentifier Resolve(CancellationToken cancellationToken)
             cache.AddPackages(InstalledPackages);
             cache.AddPackages(AdditionalPackages);
             var sw = Stopwatch.StartNew();
+
+            var packageNames = this.Packages.Select(p => p.Name).ToArray();
+            foreach (var pn in packageNames)
+            {
+                foreach (var bundlePackage in cache.Graph.GetBundlePackages(pn))
+                {
+                    this.Packages.RemoveAll(p => p.Name == bundlePackage);
+                }
+            }
 
             var resolver = new ImageResolver(cancellationToken);
 

Package/Image/PackageDependencyGraph.cs

@@ -29,6 +29,7 @@ class PackageDependencyGraph
 
         // versions contains all versions of a given name. Eg all versions of OpenTAP/
         readonly Dictionary<int, HashSet<int>> versions = new Dictionary<int, HashSet<int>>();
+        readonly Dictionary<int, string[]> bundlePackages = new Dictionary<int, string[]>();
 
         // Dependencies for a given version 
         readonly Dictionary<(int packageNameId, int packageVersion), (int packageNameId, int versionSpecifierId)[]> dependencies = new Dictionary<(int, int), (int, int)[]>();
@@ -113,6 +114,8 @@ public void LoadFromPackageDefs(IEnumerable<PackageDef> packages)
                     }
 
                     dependencies[(id, GetVersionId(version))] = deps;
+                    if (elem.IsBundle())
+                        bundlePackages[id] = elem.Dependencies.Select(dep => dep.Name).ToArray();
                 }
             }
 
@@ -124,17 +127,20 @@ public void LoadFromDictionaries(List<Dictionary<string, object>> dicts)
             {
                 var name = d["name"] as string;
                 var version = d["version"] as string;
-                if (!SemanticVersion.TryParse(version, out var v))
+                var @class = d["class"] as string;
+                if (!SemanticVersion.TryParse(version, out _))
                     continue;
                 var id = GetNameId(name);
                 var thisVersion = versions[id];
+
                 if (!thisVersion.Add(GetVersionId(version)))
                     continue; // package already added.
                 var depMap = d["dependencies"] as List<Dictionary<string, object>>;
                 if (depMap == null || depMap.Count == 0) continue;
 
                 var deps = new (int id, int y)[depMap.Count];
-                int i = 0; 
+                int i = 0;
+                var depNames = new string[depMap.Count];
                 foreach (var dep in depMap)
                 {
                     var depname = dep["name"] as string;
@@ -144,6 +150,10 @@ public void LoadFromDictionaries(List<Dictionary<string, object>> dicts)
                     i++;
                 }
 
+                if (@class?.Equals("bundle", StringComparison.InvariantCultureIgnoreCase) == true)
+                    if (!bundlePackages.ContainsKey(id))
+                        bundlePackages[id] = depNames;
+
                 dependencies[(id, GetVersionId(version))] = deps;
             }
         }
@@ -257,14 +267,18 @@ public IEnumerable<PackageDef> PackageSpecifiers()
             foreach (var thing in versions)
             {
                 var pkgName = nameLookup[thing.Key];
+                bool isBundle = bundlePackages.ContainsKey(thing.Key);
                 foreach (var v in thing.Value)
                 {
                     var version = this.versionLookup[v];
                     var pkg = new PackageDef
                     {
                         Name = pkgName,
-                        Version = version
+                        Version = version,
                     };
+                    if (isBundle)
+                        pkg.Class = "bundle";
+
                     if (dependencies.TryGetValue((thing.Key, v), out var deps))
                     {
                         foreach (var dep in deps)
@@ -367,6 +381,14 @@ public IEnumerable<PackageSpecifier> GetDependencies(string pkgName, SemanticVer
             }
         }
 
+        public string[] GetBundlePackages(string pkgName)
+        {
+            if (name2Id.TryGetValue(pkgName, out var id) && 
+                bundlePackages.TryGetValue(id, out var result))
+                return result;
+            return Array.Empty<string>();
+        }
+
         public bool HasPackage(string pkgName, SemanticVersion version)
         {
             return name2Id.TryGetValue(pkgName, out var Id)

Package/Image/PackageDependencyQuery.cs

@@ -39,7 +39,7 @@ static class PackageDependencyQuery
             var parameters = HttpPackageRepository.GetQueryParameters(version: VersionSpecifier.TryParse(preRelease, out var spec) ? spec : VersionSpecifier.AnyRelease, os: os,
                 architecture: deploymentInstallationArchitecture, name: name);
 
-            var result = repoClient.Query(parameters, CancellationToken.None, "name", "version",
+            var result = repoClient.Query(parameters, CancellationToken.None, "name", "version", "class",
                 new QuerySelection("dependencies", new List<QuerySelection>() { "name", "version" }));
             var graph = new PackageDependencyGraph();
             graph.LoadFromDictionaries(result);