Reland r64622 -

Ensure that CertStore::StoreCert never returns a cert_id of 0.

Original review URL: http://codereview.chromium.org/4181006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@64816 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/cert_store.cc

@@ -55,6 +55,10 @@ int CertStore::StoreCert(net::X509Certificate* cert, int process_id) {
   ReverseCertMap::iterator cert_iter = cert_to_id_.find(cert);
   if (cert_iter == cert_to_id_.end()) {
     cert_id = next_cert_id_++;
+    // We use 0 as an invalid cert_id value.  In the unlikely event that
+    // next_cert_id_ wraps around, we reset it to 1.
+    if (next_cert_id_ == 0)
+      next_cert_id_ = 1;
     cert->AddRef();
     id_to_cert_[cert_id] = cert;
     cert_to_id_[cert] = cert_id;