Allow invocation of --multi-install without a product if App Host needs binaries.

chrome/installer/setup/setup_main.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <windows.h>
 #include <msi.h>
 #include <shellapi.h>
 #include <shlobj.h>
 
 #include "base/at_exit.h"
@@ skipping 342 matching lines @@
     const Product* chrome_frame =
         installer_state->FindProduct(BrowserDistribution::CHROME_FRAME);
     const ProductState* cf_state =
         original_state.GetProductState(system_level,
                                        BrowserDistribution::CHROME_FRAME);
     const ProductState* chrome_state =
         original_state.GetProductState(system_level,
                                        BrowserDistribution::CHROME_BROWSER);
 
     if (!binaries) {
+      // This will only be hit if --multi-install is given with no products, or
+      // if the app host is being installed and doesn't need the binaries at
+      // user-level.
+      // The former case might be due to a request by an orphaned Application
+      // Host to re-install the binaries. Thus we add them to the installation.
+      // The latter case is fine and we let it be.
+      // If this is not an app host install and the binaries are not already
+      // present, the installation will fail later due to a lack of products to
+      // install.
       if (app_host && !chrome && !chrome_frame && !cf_state && !chrome_state) {
         DCHECK(!system_level);
         // App Host may use Chrome/Chrome binaries at system-level.
         if (original_state.GetProductState(
                 true,  // system
                 BrowserDistribution::CHROME_BROWSER) ||
             original_state.GetProductState(
                 true,  // system
                 BrowserDistribution::CHROME_BINARIES)) {
           VLOG(1) << "Installing/updating Application Host without binaries.";
-          return true;
         } else {
           // Somehow the binaries were present when the quick-enable app host
           // command was run, but now they appear to be missing.
-          // TODO(erikwright): should the binaries be implicitly added?
-          LOG(ERROR) << "Cannot install Application Host without binaries.";
-          *status = installer::APP_HOST_REQUIRES_BINARIES;
-          installer_state->WriteInstallerResult(*status, 0, NULL);
-          return false;
+          // Force binaries to be installed/updated.
+          scoped_ptr<Product> binaries_to_add(new Product(
+              BrowserDistribution::GetSpecificDistribution(
+                  BrowserDistribution::CHROME_BINARIES)));
+          binaries_to_add->SetOption(installer::kOptionMultiInstall, true);
+          binaries = installer_state->AddProduct(&binaries_to_add);
+          VLOG(1) << "Adding binaries for pre-existing App Host installation.";
         }
-      } else {
-        // Every other scenario requires the binaries to be installed/updated
-        // along with the main product.  This will only be hit if
-        // --multi-install is given with no products.  See
-        // CheckPreInstallConditions for handling of this case.
-        return true;
       }
+
+      return true;
     }
 
     if (chrome) {
       if (chrome_frame &&
           chrome_frame->HasOption(installer::kOptionReadyMode)) {
         // We're being asked to install Chrome with Chrome Frame in ready-mode.
         // This is an optimistic operation: if a SxS install of Chrome Frame
         // is already present, don't touch it; if a multi-install of Chrome
         // Frame is present, preserve its settings (ready-mode).
         if (cf_state != NULL) {
@@ skipping 1093 matching lines @@
   if (!(installer_state.is_msi() && is_uninstall))
     // Note that we allow the status installer::UNINSTALL_REQUIRES_REBOOT
     // to pass through, since this is only returned on uninstall which is
     // never invoked directly by Google Update.
     return_code = InstallUtil::GetInstallReturnCode(install_status);
 
   VLOG(1) << "Installation complete, returning: " << return_code;
 
   return return_code;
 }