Fix the path of shortcuts with an icon in the current install dir.

chrome/installer/setup/install.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 "chrome/installer/setup/install.h"
 
 #include <windows.h>
 #include <shlobj.h>
 #include <time.h>
 
@@ skipping 235 matching lines @@
     return installer::NEW_VERSION_UPDATED;
   }
 
   LOG(ERROR) << "Not sure how we got here while updating"
              << ", new version: " << new_version
              << ", old version: " << **current_version;
 
   return installer::INSTALL_FAILED;
 }
 
+// Returns the number of components in |file_path|.
+size_t GetNumPathComponents(const base::FilePath& file_path) {
+  std::vector<base::FilePath::StringType> components;
+  file_path.GetComponents(&components);
+  return components.size();
+}
+
+// Returns a path made with the |num_components| first components of
+// |file_path|. |file_path| is returned as-is if it contains less than
+// |num_components| components.
+base::FilePath TruncatePath(const base::FilePath& file_path,
+                            size_t num_components) {
+  std::vector<base::FilePath::StringType> components;
+  file_path.GetComponents(&components);
+  if (components.size() <= num_components)
+    return file_path;
+  base::FilePath truncated_file_path;
+  for (size_t i = 0; i < num_components; ++i)
+    truncated_file_path = truncated_file_path.Append(components[i]);
+  return truncated_file_path;
+}
+
 }  // namespace
 
 namespace installer {
 
 void UpdatePerUserShortcutsInLocation(
     const ShellUtil::ShortcutLocation shortcut_location,
     BrowserDistribution* dist,
     const base::FilePath& old_target_dir,
-    const base::FilePath& old_target_path_suffix,
+    const base::FilePath& old_target_name_suffix,
     const base::FilePath& new_target_path) {
   base::FilePath shortcut_path;
   const bool get_shortcut_path_return = ShellUtil::GetShortcutPath(
       shortcut_location, dist, ShellUtil::CURRENT_USER, &shortcut_path);
   DCHECK(get_shortcut_path_return);
 
   bool recursive = false;
 
   // TODO(fdoray): Modify GetShortcutPath such that it returns
   // ...\Quick Launch\User Pinned instead of
   // ...\Quick Launch\User Pinned\TaskBar for SHORTCUT_LOCATION_TASKBAR_PINS.
   if (shortcut_location == ShellUtil::SHORTCUT_LOCATION_TASKBAR_PINS) {
     shortcut_path = shortcut_path.DirName();
     recursive = true;
   }
 
+  const size_t num_old_target_dir_components =
+      GetNumPathComponents(old_target_dir);
+  InstallUtil::ProgramCompare old_target_dir_comparator(
+      old_target_dir,
+      true);  // Support directories.
+
   base::FileEnumerator shortcuts_enum(shortcut_path, recursive,
                                       base::FileEnumerator::FILES);
   for (base::FilePath shortcut = shortcuts_enum.Next(); !shortcut.empty();
        shortcut = shortcuts_enum.Next()) {
-    base::FilePath existing_target_path;
-    if (!base::win::ResolveShortcut(shortcut, &existing_target_path, nullptr) ||
-        !base::StartsWith(existing_target_path.value(),
-                          old_target_dir.AsEndingWithSeparator().value(),
-                          base::CompareCase::INSENSITIVE_ASCII) ||
-        !base::EndsWith(existing_target_path.value(),
-                        old_target_path_suffix.value(),
-                        base::CompareCase::INSENSITIVE_ASCII)) {
+    base::win::ShortcutProperties shortcut_properties;
+    if (!base::win::ResolveShortcutProperties(
+            shortcut, (base::win::ShortcutProperties::PROPERTIES_TARGET |
+                       base::win::ShortcutProperties::PROPERTIES_ICON),
+            &shortcut_properties)) {
       continue;
     }
 
+    // Skip shortcuts whose target isn't a file rooted at |old_target_dir| with
+    // a name ending in |old_target_name_suffix|. Except for shortcuts whose
+    // icon is rooted at |old_target_dir|.
+    // TODO(fdoray): The second condition is only intended to fix Canary
+    // shortcuts broken by crbug.com/595374, remove it in May 2016.
+    if (!(old_target_dir_comparator.EvaluatePath(TruncatePath(
+              shortcut_properties.target, num_old_target_dir_components)) &&

[gab, 2016/03/21 15:06:59]

Truncating to specific number of components could also be wrong right? i.e. two
paths can be the same without having the same number of components?

I guess it works to compare short vs long paths though so maybe it's okay if we
don't care about path traversals ("../") and empty components ("foo//bar/baz").

Explain in comment if so.

+          base::EndsWith(shortcut_properties.target.BaseName().value(),
+                         old_target_name_suffix.value(),
+                         base::CompareCase::INSENSITIVE_ASCII)) &&
+        !old_target_dir_comparator.EvaluatePath(TruncatePath(
+            shortcut_properties.icon, num_old_target_dir_components))) {
+      continue;
+    }
+
     base::win::ShortcutProperties updated_properties;
     updated_properties.set_target(new_target_path);
     base::win::CreateOrUpdateShortcutLink(shortcut, updated_properties,
                                           base::win::SHORTCUT_UPDATE_EXISTING);
   }
 }
 
 void EscapeXmlAttributeValueInSingleQuotes(base::string16* att_value) {
   base::ReplaceChars(*att_value, base::ASCIIToUTF16("&"),
                      base::ASCIIToUTF16("&"), att_value);
@@ skipping 407 matching lines @@
   // Read master_preferences copied beside chrome.exe at install.
   MasterPreferences prefs(installation_root.AppendASCII(kDefaultMasterPrefs));
   base::FilePath chrome_exe(installation_root.Append(kChromeExe));
   CreateOrUpdateShortcuts(
       chrome_exe, chrome, prefs, CURRENT_USER, install_operation);
 
   UpdateDefaultBrowserBeaconForPath(chrome_exe);
 }
 
 }  // namespace installer