[Extensions] Log instances of invalid extensions being added

chrome/browser/extensions/extension_service.cc

 // Copyright (c) 2013 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/browser/extensions/extension_service.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <iterator>
 #include <memory>
 #include <set>
 #include <utility>
 
 #include "base/command_line.h"
+#include "base/debug/alias.h"
+#include "base/debug/dump_without_crashing.h"
 #include "base/location.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/single_thread_task_runner.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_tokenizer.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/threading/sequenced_worker_pool.h"
 #include "base/threading/thread_restrictions.h"
 #include "base/threading/thread_task_runner_handle.h"
@@ skipping 1448 matching lines @@
       to_enable.push_back(extension);
   }
   for (const auto& extension : to_enable) {
     EnableExtension(extension->id());
   }
 
   OnBlacklistUpdated();
 }
 
 void ExtensionService::AddExtension(const Extension* extension) {
+  if (!Manifest::IsValidLocation(extension->location())) {
+    // TODO(devlin): We should *never* add an extension with an invalid
+    // location, but some bugs (e.g. crbug.com/692069) seem to indicate we do.
+    // Track down the cases when this can happen, and remove this
+    // DumpWithoutCrashing() (possibly replacing it with a CHECK).
+    NOTREACHED();
+    char extension_id_copy[32];

[lazyboy, 2017/03/08 19:01:01]

I think you need 33 here, b/c of strlcpy.

[Devlin, 2017/03/09 01:23:38]

done.

+    base::strlcpy(extension_id_copy, extension->id().c_str(),
+                  arraysize(extension_id_copy));
+    Manifest::Location location = extension->location();
+    int creation_flags = extension->creation_flags();
+    Manifest::Type type = extension->manifest()->type();
+    base::debug::Alias(extension_id_copy);
+    base::debug::Alias(&location);
+    base::debug::Alias(&creation_flags);
+    base::debug::Alias(&type);
+    base::debug::DumpWithoutCrashing();
+    return;
+  }
+
   // TODO(jstritar): We may be able to get rid of this branch by overriding the
   // default extension state to DISABLED when the --disable-extensions flag
   // is set (http://crbug.com/29067).
   if (!extensions_enabled() && !extension->is_theme() &&
       extension->location() != Manifest::COMPONENT &&
       !Manifest::IsExternalLocation(extension->location()) &&
       disable_flag_exempted_extensions_.count(extension->id()) == 0) {
     return;
   }
 
@@ skipping 1026 matching lines @@
 }
 
 void ExtensionService::OnProfileDestructionStarted() {
   ExtensionIdSet ids_to_unload = registry_->enabled_extensions().GetIDs();
   for (ExtensionIdSet::iterator it = ids_to_unload.begin();
        it != ids_to_unload.end();
        ++it) {
     UnloadExtension(*it, UnloadedExtensionInfo::REASON_PROFILE_SHUTDOWN);
   }
 }