Bug 1534339 - make OriginAttributes deserializable; r=baku

`CreateSuffix` is irreversible by `PopulateFromSuffix` because it uses a multi-to-one mapping.
Since only ':' will happen in a IPv6 format, we can make it a 1-to-1 mapping so that the `firstPartyDomain` is consistent after `CreateSuffix` and `PopulateFromSuffix`.

Differential Revision: https://phabricator.services.mozilla.com/D47910

--HG--
extra : moz-landing-system : lando

caps/OriginAttributes.cpp

@@ -13,6 +13,9 @@
 #include "nsIURI.h"
 #include "nsURLHelper.h"
 
+static const char kSourceChar = ':';
+static const char kSanitizedChar = '+';
+
 namespace mozilla {
 
 using dom::URLParams;
@@ -140,8 +143,7 @@ void OriginAttributes::CreateSuffix(nsACString& aStr) const {
 
   if (!mFirstPartyDomain.IsEmpty()) {
     nsAutoString sanitizedFirstPartyDomain(mFirstPartyDomain);
-    sanitizedFirstPartyDomain.ReplaceChar(
-        dom::quota::QuotaManager::kReplaceChars, '+');
+    sanitizedFirstPartyDomain.ReplaceChar(kSourceChar, kSanitizedChar);
 
     params.Set(NS_LITERAL_STRING("firstPartyDomain"),
                sanitizedFirstPartyDomain);
@@ -150,7 +152,7 @@ void OriginAttributes::CreateSuffix(nsACString& aStr) const {
   if (!mGeckoViewSessionContextId.IsEmpty()) {
     nsAutoString sanitizedGeckoViewUserContextId(mGeckoViewSessionContextId);
     sanitizedGeckoViewUserContextId.ReplaceChar(
-        dom::quota::QuotaManager::kReplaceChars, '+');
+        dom::quota::QuotaManager::kReplaceChars, kSanitizedChar);
 
     params.Set(NS_LITERAL_STRING("geckoViewUserContextId"),
                sanitizedGeckoViewUserContextId);
@@ -237,7 +239,9 @@ class MOZ_STACK_CLASS PopulateFromSuffixIterator final
 
     if (aName.EqualsLiteral("firstPartyDomain")) {
       MOZ_RELEASE_ASSERT(mOriginAttributes->mFirstPartyDomain.IsEmpty());
-      mOriginAttributes->mFirstPartyDomain.Assign(aValue);
+      nsAutoString firstPartyDomain(aValue);
+      firstPartyDomain.ReplaceChar(kSanitizedChar, kSourceChar);
+      mOriginAttributes->mFirstPartyDomain.Assign(firstPartyDomain);
       return true;
     }
 

caps/tests/gtest/TestOriginAttributes.cpp

@@ -26,6 +26,8 @@ static void TestFPD(const nsAString& spec, const nsAString& fpd) {
   ASSERT_EQ(NS_NewURI(getter_AddRefs(url), spec), NS_OK);
   attrs.SetFirstPartyDomain(true, url);
   EXPECT_TRUE(attrs.mFirstPartyDomain.Equals(fpd));
+
+  TestSuffix(attrs);
 }
 
 TEST(OriginAttributes, Suffix_default)