Fix a bug in hostpolicy initialization for nativehost

Author: swaroop-sridhar

src/installer/corehost/cli/hostpolicy/args.cpp

@@ -102,6 +102,47 @@ bool parse_arguments(
         args);
 }
 
+bool set_root_from_app(const pal::string_t& managed_application_path,
+                       arguments_t& args)
+{
+    args.managed_application = managed_application_path;
+
+    if (args.managed_application.empty())
+    {
+        // Managed app being empty by itself is not a failure. Host may be initialized from a config file. 
+        assert(args.host_mode != host_mode_t::apphost);
+        return true;
+    }
+
+    if (bundle::info_t::is_single_file_bundle())
+    {
+        const bundle::runner_t* app = bundle::runner_t::app();
+        args.app_root = app->base_path();
+
+        // Check for the main app within the bundle.
+        // locate() sets args.managed_application to the full path of the app extracted to disk.
+        pal::string_t managed_application_name = get_filename(managed_application_path);		
+        if (app->locate(managed_application_name, args.managed_application))
+        {
+            return true;
+        }
+
+        trace::info(_X("Managed application [%s] not found in single-file bundle"), managed_application_name.c_str());
+		
+        // If the main assembly is not found in the bundle, continue checking on disk
+        // for very unlikely case where the main app.dll was itself excluded from the app bundle.
+        return pal::realpath(&args.managed_application);
+    }
+
+    if (pal::realpath(&args.managed_application))
+    {
+        args.app_root = get_directory(managed_application_path);
+        return true;
+    }
+
+    return false;
+}
+
 bool init_arguments(
     const pal::string_t& managed_application_path,
     const host_startup_info_t& host_info,
@@ -116,39 +157,7 @@ bool init_arguments(
     args.host_path = host_info.host_path;
     args.additional_deps_serialized = additional_deps_serialized;
 
-    if (!managed_application_path.empty())
-    {
-        pal::string_t managed_application_name = get_filename(managed_application_path);
-        if (bundle::info_t::is_single_file_bundle())
-        {
-            args.app_root = bundle::runner_t::app()->base_path();
-            const bundle::runner_t* app = bundle::runner_t::app();
-
-            // Check for the main app within the bundle.
-            if (!app->locate(managed_application_name, args.managed_application))
-            {
-                // If the main app is not found in the bundle, check beside the bundle
-                // for very unlikely case where the main app.dll was itself excluded from the app bundle.
-                args.managed_application = managed_application_path;
-                if (!pal::realpath(&args.managed_application))
-                {
-                    trace::error(_X("Failed to locate managed application [%s]"), args.managed_application.c_str());
-                    return false;
-                }
-            }
-        }
-        else
-        {
-            args.app_root = get_directory(managed_application_path);
-            args.managed_application = managed_application_path;
-            if (!pal::realpath(&args.managed_application))
-            {
-                trace::error(_X("Failed to locate managed application [%s]"), args.managed_application.c_str());
-                return false;
-            }
-        }
-    }
-    else
+    if (!set_root_from_app(managed_application_path, args))
     {
         trace::error(_X("Failed to locate managed application [%s]"), args.managed_application.c_str());
         return false;