Make IP Address related functions return the empty string when used on an invalid address.

net/base/ip_address_number_unittest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/base/ip_address_number.h"
 
 #include "base/format_macros.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/stringprintf.h"
 #include "net/base/net_util.h"
@@ skipping 16 matching lines @@
 
 TEST(IpAddressNumberTest, IPAddressToString) {
   uint8_t addr1[4] = {0, 0, 0, 0};
   EXPECT_EQ("0.0.0.0", IPAddressToString(addr1, sizeof(addr1)));
 
   uint8_t addr2[4] = {192, 168, 0, 1};
   EXPECT_EQ("192.168.0.1", IPAddressToString(addr2, sizeof(addr2)));
 
   uint8_t addr3[16] = {0xFE, 0xDC, 0xBA, 0x98};
   EXPECT_EQ("fedc:ba98::", IPAddressToString(addr3, sizeof(addr3)));
+
+  // IPAddressToString() shouldn't crash on invalid addresses.
+  uint8_t addr4[2];

[Nico, 2016/02/17 02:27:43]

Doesn't this have to be 4 bytes? Also, should it be initialized to something?
Else this has undefined behavior

[martijnc, 2016/02/17 08:29:53]

The length of 2 bytes is correct. This tests if IPAddressToString() returns an
empty string when called with an invalid address. The contents isn't used when
the IP has invalid length.

I'll take a look why these are failing in debug builds when I get home. Should
this be reverted in the meantime?

+  EXPECT_EQ("", IPAddressToString(addr4, sizeof(addr4)));
 }
 
 TEST(IpAddressNumberTest, IPAddressToStringWithPort) {
   uint8_t addr1[4] = {0, 0, 0, 0};
   EXPECT_EQ("0.0.0.0:3", IPAddressToStringWithPort(addr1, sizeof(addr1), 3));
 
   uint8_t addr2[4] = {192, 168, 0, 1};
   EXPECT_EQ("192.168.0.1:99",
             IPAddressToStringWithPort(addr2, sizeof(addr2), 99));
 
   uint8_t addr3[16] = {0xFE, 0xDC, 0xBA, 0x98};
   EXPECT_EQ("[fedc:ba98::]:8080",
             IPAddressToStringWithPort(addr3, sizeof(addr3), 8080));
+
+  // IPAddressToStringWithPort() shouldn't crash on invalid addresses.
+  uint8_t addr4[2];
+  EXPECT_EQ("", IPAddressToStringWithPort(addr4, sizeof(addr4), 8080));
 }
 
 // Test that invalid IP literals fail to parse.
 TEST(IpAddressNumberTest, ParseIPLiteralToNumber_FailParse) {
   IPAddressNumber number;
 
   EXPECT_FALSE(ParseIPLiteralToNumber("bad value", &number));
   EXPECT_FALSE(ParseIPLiteralToNumber("bad:value", &number));
   EXPECT_FALSE(ParseIPLiteralToNumber(std::string(), &number));
   EXPECT_FALSE(ParseIPLiteralToNumber("192.168.0.1:30", &number));
@@ skipping 197 matching lines @@
     EXPECT_EQ(tests[i].expected_to_match,
               IPNumberMatchesPrefix(ip_number,
                                     ip_prefix,
                                     prefix_length_in_bits));
   }
 }
 
 }  // anonymous namespace
 
 }  // namespace net