dns-prefetch: whitelist Safari 6+

Fixes #1348

Author: jeffkaufman

pagespeed/kernel/http/user_agent_matcher.cc

@@ -207,11 +207,10 @@ const char* kWebpAnimatedBlacklist[] = {
   "*CriOS/31.*",
 };
 
-// TODO(rahulbansal): We haven't added Safari here since it supports dns
-// prefetch only from 5.0.1 which causes the wildcard to be a bit messy.
 const char* kInsertDnsPrefetchWhitelist[] = {
   "*Chrome/*",
   "*Firefox/*",
+  "*Safari/*",
   // Plus IE, see code below.
   "*Wget*",
   // The following user agents are used only for internal testing
@@ -222,6 +221,15 @@ const char* kInsertDnsPrefetchBlacklist[] = {
   "*Firefox/1.*",
   "*Firefox/2.*",
   "*Firefox/3.*",
+  // Safari indicates version with a separate Version/N.N.N token that appears
+  // somewhere before the Safari/ token.  This only started with version 3, but
+  // versions before 3 are 10+ years old at this point and won't run on any
+  // supported OS.
+  "*Version/3.*Safari/*",
+  "*Version/4.*Safari/*",
+  // 5.0.1+ actually did support it, but that's long obsolete, so don't bother
+  // contorting the list to include it.
+  "*Version/5.*Safari/*",
   "*MSIE 5.*",
   "*MSIE 6.*",
   "*MSIE 7.*",

pagespeed/kernel/http/user_agent_matcher_test.cc

@@ -438,6 +438,10 @@ TEST_F(UserAgentMatcherTest, SupportsDnsPrefetch) {
       kIe9UserAgent));
   EXPECT_TRUE(user_agent_matcher_->SupportsDnsPrefetch(
       kFirefox5UserAgent));
+  EXPECT_TRUE(user_agent_matcher_->SupportsDnsPrefetch(
+      kSafari6UserAgent));
+  EXPECT_TRUE(user_agent_matcher_->SupportsDnsPrefetch(
+      kSafari9UserAgent));
   for (int i = 0; i < kIe11UserAgentsArraySize; ++i) {
     EXPECT_TRUE(user_agent_matcher_->SupportsDnsPrefetch(
         kIe11UserAgents[i]));

pagespeed/kernel/http/user_agent_matcher_test_base.cc

@@ -277,6 +277,12 @@ const char UserAgentMatcherTestBase::kRoverUserAgent[] =
 const char UserAgentMatcherTestBase::kSafariUserAgent[] =
     "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_6_8) AppleWebKit/534.51.22 "
     "(KHTML, like Gecko) Version/5.1.1 Safari/534.51.22";
+const char UserAgentMatcherTestBase::kSafari6UserAgent[] =
+    "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_7_4) AppleWebKit/536.25 "
+    "(KHTML, like Gecko) Version/6.0 Safari/536.25";
+const char UserAgentMatcherTestBase::kSafari9UserAgent[] =
+    "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_5) AppleWebKit/601.6.17 "
+    "(KHTML, like Gecko) Version/9.1.1 Safari/601.6.17";
 const char UserAgentMatcherTestBase::kSAGEMMobileUserAgent[] =
     "SAGEM-my202C/Orange1.0 UP.Browser/5.0.5.6 (GUI)";
 const char UserAgentMatcherTestBase::kSAGEMUserAgent[] =

pagespeed/kernel/http/user_agent_matcher_test_base.h

@@ -123,6 +123,8 @@ class UserAgentMatcherTestBase : public testing::Test {
   static const char kPSPUserAgent[];
   static const char kRoverUserAgent[];
   static const char kSafariUserAgent[];
+  static const char kSafari6UserAgent[];
+  static const char kSafari9UserAgent[];
   static const char kSAGEMMobileUserAgent[];
   static const char kSAGEMUserAgent[];
   static const char kSAMSUNGMobileUserAgent[];