Backed out changeset 3cdcc72baa6e (bug 1776755) for causing failures at test_ext_contentscript_triggeringPrincipal.js.

caps/BasePrincipal.h

@@ -410,16 +410,6 @@ inline bool BasePrincipal::FastEqualsConsideringDomain(nsIPrincipal* aOther) {
     return FastEquals(aOther);
   }
 
-  // Principals of different kinds can't be equal.
-  if (Kind() != other->Kind()) {
-    return false;
-  }
-
-  // Only ContentPrincipals should have mHasExplicitDomain set to true, so test
-  // that we haven't ended up here instead of FastEquals by mistake.
-  MOZ_ASSERT(IsContentPrincipal(),
-             "Only content principals can set mHasExplicitDomain");
-
   return Subsumes(aOther, ConsiderDocumentDomain) &&
          other->Subsumes(this, ConsiderDocumentDomain);
 }

caps/ExpandedPrincipal.cpp

@@ -20,6 +20,28 @@ NS_IMPL_QUERY_INTERFACE_CI(ExpandedPrincipal, nsIPrincipal,
 NS_IMPL_CI_INTERFACE_GETTER(ExpandedPrincipal, nsIPrincipal,
                             nsIExpandedPrincipal)
 
+struct OriginComparator {
+  bool LessThan(nsIPrincipal* a, nsIPrincipal* b) const {
+    nsAutoCString originA;
+    DebugOnly<nsresult> rv = a->GetOrigin(originA);
+    MOZ_ASSERT(NS_SUCCEEDED(rv));
+    nsAutoCString originB;
+    rv = b->GetOrigin(originB);
+    MOZ_ASSERT(NS_SUCCEEDED(rv));
+    return originA < originB;
+  }
+
+  bool Equals(nsIPrincipal* a, nsIPrincipal* b) const {
+    nsAutoCString originA;
+    DebugOnly<nsresult> rv = a->GetOrigin(originA);
+    MOZ_ASSERT(NS_SUCCEEDED(rv));
+    nsAutoCString originB;
+    rv = b->GetOrigin(originB);
+    MOZ_ASSERT(NS_SUCCEEDED(rv));
+    return a == b;
+  }
+};
+
 ExpandedPrincipal::ExpandedPrincipal(
     nsTArray<nsCOMPtr<nsIPrincipal>>&& aPrincipals,
     const nsACString& aOriginNoSuffix, const OriginAttributes& aAttrs)
@@ -31,9 +53,12 @@ ExpandedPrincipal::~ExpandedPrincipal() = default;
 already_AddRefed<ExpandedPrincipal> ExpandedPrincipal::Create(
     const nsTArray<nsCOMPtr<nsIPrincipal>>& aAllowList,
     const OriginAttributes& aAttrs) {
+  // We force the principals to be sorted by origin so that ExpandedPrincipal
+  // origins can have a canonical form.
   nsTArray<nsCOMPtr<nsIPrincipal>> principals;
+  OriginComparator c;
   for (size_t i = 0; i < aAllowList.Length(); ++i) {
-    principals.AppendElement(aAllowList[i]);
+    principals.InsertElementSorted(aAllowList[i], c);
   }
 
   nsAutoCString origin;
@@ -223,6 +248,7 @@ ExpandedPrincipal::Deserializer::Read(nsIObjectInputStream* aStream) {
     return NS_ERROR_OUT_OF_MEMORY;
   }
 
+  OriginComparator c;
   for (uint32_t i = 0; i < count; ++i) {
     nsCOMPtr<nsISupports> read;
     rv = aStream->ReadObject(true, getter_AddRefs(read));
@@ -235,7 +261,9 @@ ExpandedPrincipal::Deserializer::Read(nsIObjectInputStream* aStream) {
       return NS_ERROR_UNEXPECTED;
     }
 
-    principals.AppendElement(std::move(principal));
+    // Play it safe and InsertElementSorted, in case the sort order
+    // changed for some bizarre reason.
+    principals.InsertElementSorted(std::move(principal), c);
   }
 
   mPrincipal = ExpandedPrincipal::Create(principals, OriginAttributes());

js/xpconnect/tests/unit/test_allowedDomainsXHR.js

@@ -63,7 +63,7 @@ function run_test()
 
   var principal = res.responseXML.nodePrincipal;
   Assert.ok(principal.isContentPrincipal);
-  var requestURL = "http://localhost:4444/redirect";
+  var requestURL = "http://localhost:4444/simple";
   Assert.equal(principal.spec, requestURL);
 
   // negative test sync XHR sending (to ensure that the xhr do not have chrome caps, see bug 779821)
@@ -85,7 +85,7 @@ function run_test()
 
   var principal = res.responseXML.nodePrincipal;
   Assert.ok(principal.isContentPrincipal);
-  var requestURL = "http://localhost:4444/redirect";
+  var requestURL = "http://localhost:4444/simple";
   Assert.equal(principal.spec, requestURL);
 
   httpserver2.stop(finishIfDone);