Allow custom deleters to opt out of self reset checks for scoped_ptr.

net/ssl/openssl_client_key_store.cc

Index: net/ssl/openssl_client_key_store.cc
diff --git a/net/ssl/openssl_client_key_store.cc b/net/ssl/openssl_client_key_store.cc
index b0b5eb3d4753d14a8ae186ba4fabfae1b927d243..ae2da60491fecd282fa0bce1b42bc75212e195fe 100644
--- a/net/ssl/openssl_client_key_store.cc
+++ b/net/ssl/openssl_client_key_store.cc
@@ -6,6 +6,7 @@
 
 #include <openssl/evp.h>
 #include <openssl/x509.h>
+#include <algorithm>
 
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/singleton.h"
@@ -50,15 +51,15 @@ OpenSSLClientKeyStore::KeyPair::KeyPair(const KeyPair& other)
       private_key(EVP_PKEY_dup(other.private_key.get())) {
 }
 
-void OpenSSLClientKeyStore::KeyPair::operator=(const KeyPair& other) {
-  // Use a temporary ScopedEVP_PKEY because scoped_ptr does not allow resetting
-  // to the current value, even though it's safe here.
-  crypto::ScopedEVP_PKEY public_key_tmp(EVP_PKEY_dup(other.public_key.get()));
-  crypto::ScopedEVP_PKEY private_key_tmp(EVP_PKEY_dup(other.private_key.get()));
-  public_key.reset();
-  public_key = public_key_tmp.Pass();
-  private_key.reset();
-  private_key = private_key_tmp.Pass();
+void OpenSSLClientKeyStore::KeyPair::operator=(KeyPair other) {
+  this->swap(other);
+}
+
+// Intentionally pass by value, in order to use the copy-and-swap idiom.

[pneubeck (no reviews), 2014/10/07 09:30:09]

should this comment better be at the operator= function?

[dcheng, 2014/10/07 22:40:37]

I'm ambivalent on this. I felt like it was better to describe the idiom where it
actually appeared, but I don't think putting it in the header is wrong either.
So moved. Done.

+void OpenSSLClientKeyStore::KeyPair::swap(KeyPair& other) {
+  using std::swap;
+  swap(public_key, other.public_key);
+  swap(private_key, other.private_key);
 }
 
 int OpenSSLClientKeyStore::FindKeyPairIndex(EVP_PKEY* public_key) {