From 7ccfefc766cc09064823ae19e886e17188d44a46 Mon Sep 17 00:00:00 2001
From: Pavlo Kushnir <pavlo@fb.com>
Date: Sun, 6 Jul 2014 21:03:36 -0700
Subject: [PATCH] Fix IPAddress operator==

Summary: IPAddress operator== throws an exception when comparing ip v6 mapped address with unitialized (default constructed) address. With this diff it returns false.

Test Plan: folly unit tests

Reviewed By: bmatheny@fb.com

FB internal diff: D1421280
---
 folly/IPAddress.cpp          |  4 ++--
 folly/test/IPAddressTest.cpp | 20 ++++++++++++++++++++
 2 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/folly/IPAddress.cpp b/folly/IPAddress.cpp
index 01642104..b49b0dc8 100644
--- a/folly/IPAddress.cpp
+++ b/folly/IPAddress.cpp
@@ -330,13 +330,13 @@ bool operator==(const IPAddress& addr1, const IPAddress& addr2) {
     }
   }
   // addr1 is v4 mapped v6 address, addr2 is v4
-  if (addr1.isIPv4Mapped()) {
+  if (addr1.isIPv4Mapped() && addr2.isV4()) {
     if (IPAddress::createIPv4(addr1) == addr2.asV4()) {
       return true;
     }
   }
   // addr2 is v4 mapped v6 address, addr1 is v4
-  if (addr2.isIPv4Mapped()) {
+  if (addr2.isIPv4Mapped() && addr1.isV4()) {
     if (IPAddress::createIPv4(addr2) == addr1.asV4()) {
       return true;
     }
diff --git a/folly/test/IPAddressTest.cpp b/folly/test/IPAddressTest.cpp
index 039999e6..d72a2b90 100644
--- a/folly/test/IPAddressTest.cpp
+++ b/folly/test/IPAddressTest.cpp
@@ -435,6 +435,26 @@ TEST_P(IPAddressMaskBoundaryTest, NonMaskedSubnet) {
   EXPECT_EQ(param.inSubnet, ip.inSubnet(subnet, param.mask));
 }
 
+TEST(IPAddress, UnitializedEqual) {
+  IPAddress addrEmpty;
+  IPAddress ip4("127.0.0.1");
+  EXPECT_FALSE(addrEmpty == ip4);
+  EXPECT_FALSE(ip4 == addrEmpty);
+  IPAddress ip6("::1");
+  EXPECT_FALSE(addrEmpty == ip6);
+  EXPECT_FALSE(ip6 == addrEmpty);
+  IPAddress ip6Map("::ffff:192.0.2.129");
+  EXPECT_FALSE(addrEmpty == ip6Map);
+  EXPECT_FALSE(ip6Map == addrEmpty);
+  IPAddress ip4Zero("0.0.0.0");
+  EXPECT_FALSE(addrEmpty == ip4Zero);
+  EXPECT_FALSE(ip4Zero == addrEmpty);
+  IPAddress ip6Zero("::");
+  EXPECT_FALSE(addrEmpty == ip6Zero);
+  EXPECT_FALSE(ip6Zero == addrEmpty);
+  EXPECT_EQ(addrEmpty, addrEmpty);
+}
+
 // Test subnet calcs with 6to4 addresses
 TEST(IPAddress, InSubnetWith6to4) {
   auto ip = IPAddress("2002:c000:022a::"); // 192.0.2.42
-- 
2.34.1