Do machine inspection on install....

chrome/installer/util/helper.cc

Index: chrome/installer/util/helper.cc
===================================================================
--- chrome/installer/util/helper.cc	(revision 70232)
+++ chrome/installer/util/helper.cc	(working copy)
@@ -41,18 +41,38 @@
 
 bool IsInstalledAsMulti(bool system_install, BrowserDistribution* dist) {
   bool installed_as_multi = false;
-  HKEY root = system_install ? HKEY_LOCAL_MACHINE : HKEY_CURRENT_USER;
-  RegKey key(root, dist->GetStateKey().c_str(), KEY_READ);
-  if (key.Valid()) {
-    std::wstring args;
-    key.ReadValue(installer::kUninstallArgumentsField, &args);
-    if (!args.empty()) {
-      args.insert(0, L"fake.exe ");
-      CommandLine cmd(CommandLine::FromString(args));
-      installed_as_multi = cmd.HasSwitch(installer::switches::kMultiInstall);
+  CommandLine cmd(CommandLine::NO_PROGRAM);
+  if (GetUninstallSwitches(system_install, dist, &cmd))
+    installed_as_multi = cmd.HasSwitch(installer::switches::kMultiInstall);
+  return installed_as_multi;
+}
+
+bool GetUninstallSwitches(bool system_install, BrowserDistribution* dist,
+                          CommandLine* cmd_line_switches) {
+  scoped_ptr<Version> installed(InstallUtil::GetChromeVersion(dist,
+                                                              system_install));
+  if (installed.get()) {
+    HKEY root = system_install ? HKEY_LOCAL_MACHINE : HKEY_CURRENT_USER;
+    RegKey key(root, dist->GetStateKey().c_str(), KEY_READ);
+    if (key.Valid()) {
+      std::wstring args;
+      key.ReadValue(installer::kUninstallArgumentsField, &args);
+      if (!args.empty()) {
+        args.insert(0, L"foo.exe ");
+        *cmd_line_switches = CommandLine::FromString(args);
+      } else {
+        LOG(ERROR) << "No uninstallation arguments for "

[grt (UTC plus 2), 2010/12/29 16:51:50]

Are these two ERROR conditions bad enough that we should abort installation?  In
other words, will all callers do something that will be non-harmful in these
cases?

[tommi (sloooow) - chröme, 2010/12/29 17:30:09]

I was thinking the same but in the end opted on the side of "things must be
pretty messed up for this to happen and if the installer is being run, it will
likely fix it".
It's also non trivial to back out from here.

+                   << dist->GetApplicationName();
+        installed.reset();
+      }
+    } else {
+      LOG(ERROR) << "Product looks to be installed but we can't access the "
+                    "state key: " << dist->GetApplicationName();
+      installed.reset();
     }
   }
-  return installed_as_multi;
+
+  return installed.get() != NULL;
 }
 
 FilePath GetChromeInstallPath(bool system_install, BrowserDistribution* dist) {