Unregister previous ChromeFrame UA strings registered under the PostPlatform ...

chrome_frame/chrome_tab.cc

Index: chrome_frame/chrome_tab.cc
===================================================================
--- chrome_frame/chrome_tab.cc	(revision 71338)
+++ chrome_frame/chrome_tab.cc	(working copy)
@@ -8,6 +8,7 @@
 #include "chrome_tab.h"  // NOLINT
 
 #include <atlsecurity.h>
+#include <vector>
 
 #include "base/at_exit.h"
 #include "base/command_line.h"
@@ -426,6 +427,23 @@
     L"User Agent\\Post Platform";
 const wchar_t kChromeFramePrefix[] = L"chromeframe/";
 
+// Returns the list of chrome frame UA agents registered under the
+// kPostPlatformUAKey registry key.
+void GetRegisteredChromeFrameUAStrings(HKEY parent_hive,
+                                       std::vector<std::wstring>* ua_values) {
+  base::win::RegistryValueIterator ua_registration(parent_hive,
+                                                   kPostPlatformUAKey);
+  std::wstring chrome_frame_ua_pattern = kChromeFramePrefix;
+  chrome_frame_ua_pattern += L"*";
+  while (ua_registration.Valid()) {
+    if (MatchPattern(ua_registration.Name(),
+                     chrome_frame_ua_pattern)) {
+      ua_values->push_back(ua_registration.Name());
+    }
+    ++ua_registration;
+  }
+}
+
 // To delete the user agent, set value to NULL.
 // The is_system parameter indicates whether this is a per machine or a per
 // user installation.
@@ -433,11 +451,21 @@
   HRESULT hr = E_FAIL;
   HKEY parent_hive = is_system ? HKEY_LOCAL_MACHINE : HKEY_CURRENT_USER;
 
+  // If we are registering the ChromeFrame UA in the kPostPlatformUAKey key

[amit, 2011/01/14 05:26:01]

why not delete all the matching values anyway? If |value| is not NULL then we
just have to write a new value.

+  // make sure that we unregister ChromeFrame UA strings registered by previous
+  // ChromeFrame versions.
+  std::vector<std::wstring> cf_ua_list;
+  if (value) {
+    GetRegisteredChromeFrameUAStrings(parent_hive, &cf_ua_list);
+  }
   RegKey ua_key;
   if (ua_key.Create(parent_hive, kPostPlatformUAKey, KEY_WRITE)) {
     std::wstring chrome_frame_ua_value_name = kChromeFramePrefix;
     chrome_frame_ua_value_name += GetCurrentModuleVersion();
     if (value) {
+      for (size_t ua_idx = 0; ua_idx < cf_ua_list.size(); ua_idx++) {
+        ua_key.DeleteValue(cf_ua_list[ua_idx].c_str());
+      }
       ua_key.WriteValue(chrome_frame_ua_value_name.c_str(), value);
     } else {
       ua_key.DeleteValue(chrome_frame_ua_value_name.c_str());