Trial and group names can have '.' which should be escaped properly.

When trial and group names are outputed to string special characters are
escaped. However '.' and '*' are not escaped.

Bug: 694675
Change-Id: I52583ee8f05f0dd49c6a4b28b03881054014625a
Reviewed-on: https://chromium-review.googlesource.com/988267
Commit-Queue: Gayane Petrosyan <gayane@chromium.org>
Reviewed-by: Alexei Svitkine <asvitkine@chromium.org>
Reviewed-by: Will Harris <wfh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#554866}

components/variations/field_trial_config/field_trial_util.cc

@@ -21,12 +21,6 @@
 namespace variations {
 namespace {
 
-std::string UnescapeValue(const std::string& value) {
-  return net::UnescapeURLComponent(
-      value, net::UnescapeRule::PATH_SEPARATORS |
-                 net::UnescapeRule::URL_SPECIAL_CHARS_EXCEPT_PATH_SEPARATORS);
-}
-
 void AssociateParamsFromExperiment(
     const std::string& study_name,
     const FieldTrialTestingExperiment& experiment,
@@ -83,10 +77,30 @@ const FieldTrialTestingExperiment& ChooseExperiment(
 
 } // namespace
 
+std::string UnescapeValue(const std::string& value) {
+  return net::UnescapeURLComponent(
+      value, net::UnescapeRule::PATH_SEPARATORS |
+                 net::UnescapeRule::URL_SPECIAL_CHARS_EXCEPT_PATH_SEPARATORS);
+}
+
 std::string EscapeValue(const std::string& value) {
   // This needs to be the inverse of UnescapeValue in the anonymous namespace
   // above.
-  return net::EscapeQueryParamValue(value, true /* use_plus */);
+  std::string net_escaped_str =
+      net::EscapeQueryParamValue(value, true /* use_plus */);
+
+  // net doesn't escape '.' and '*' but UnescapeValue() covers those cases.
+  std::string escaped_str;
+  escaped_str.reserve(net_escaped_str.length());
+  for (const char ch : net_escaped_str) {
+    if (ch == '.')
+      escaped_str.append("%2E");
+    else if (ch == '*')
+      escaped_str.append("%2A");
+    else
+      escaped_str.push_back(ch);
+  }
+  return escaped_str;
 }
 
 bool AssociateParamsFromString(const std::string& varations_string) {

components/variations/field_trial_config/field_trial_util.h

@@ -15,6 +15,9 @@ namespace variations {
 
 struct FieldTrialTestingConfig;
 
+// Unescapes special characters from the given string.
+std::string UnescapeValue(const std::string& value);
+
 // Escapes the trial name, or parameter name, or parameter value in a way that
 // makes it usable within variations::switches::kForceFieldTrialParams.
 std::string EscapeValue(const std::string& value);

components/variations/field_trial_config/field_trial_util_unittest.cc

@@ -177,4 +177,15 @@ TEST_F(FieldTrialUtilTest, AssociateForcingFlagsFromFieldTrialConfig) {
   EXPECT_EQ("ForcedGroup3", base::FieldTrialList::FindFullName("TestTrial3"));
 }
 
+TEST_F(FieldTrialUtilTest, TestEscapeValue) {
+  std::string str = "trail.:/,*";
+  std::string escaped_str = EscapeValue(str);
+  EXPECT_EQ(escaped_str.find('.'), std::string::npos);
+  EXPECT_EQ(escaped_str.find(':'), std::string::npos);
+  EXPECT_EQ(escaped_str.find('/'), std::string::npos);
+  EXPECT_EQ(escaped_str.find(','), std::string::npos);
+  EXPECT_EQ(escaped_str.find('*'), std::string::npos);
+
+  EXPECT_EQ(str, UnescapeValue(escaped_str));
+}
 }  // namespace variations