Bug 1521878 - Have fallback consistency for (de)serialization of principals. r=ckerschb

Differential Revision: https://phabricator.services.mozilla.com/D17271

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

browser/base/content/browser.js

@@ -3105,7 +3105,7 @@ var BrowserOnClick = {
   },
 
   ignoreWarningLink(reason, blockedInfo) {
-    let triggeringPrincipal = E10SUtils.deserializePrincipal(blockedInfo.triggeringPrincipal) || _createNullPrincipalFromTabUserContextId();
+    let triggeringPrincipal = E10SUtils.deserializePrincipal(blockedInfo.triggeringPrincipal, _createNullPrincipalFromTabUserContextId());
     // Allow users to override and continue through to the site,
     // but add a notify bar as a reminder, so that they don't lose
     // track after, e.g., tab switching.

browser/components/sessionstore/ContentRestore.jsm

@@ -213,9 +213,7 @@ ContentRestoreInternal.prototype = {
         }
         let postData = loadArguments.postData ?
                        E10SUtils.makeInputStream(loadArguments.postData) : null;
-        let triggeringPrincipal = loadArguments.triggeringPrincipal
-                                  ? E10SUtils.deserializePrincipal(loadArguments.triggeringPrincipal)
-                                  : Services.scriptSecurityManager.createNullPrincipal({});
+        let triggeringPrincipal = E10SUtils.deserializePrincipal(loadArguments.triggeringPrincipal, () => Services.scriptSecurityManager.createNullPrincipal({}));
 
         if (loadArguments.userContextId) {
           webNavigation.setOriginAttributesBeforeLoading({ userContextId: loadArguments.userContextId });

toolkit/actors/WebNavigationChild.jsm

@@ -104,12 +104,11 @@ class WebNavigationChild extends ActorChild {
     if (baseURI)
       baseURI = Services.io.newURI(baseURI);
     this._assert(triggeringPrincipal, "We need a triggering principal to continue loading", new Error().lineNumber);
-    if (triggeringPrincipal)
-      triggeringPrincipal = E10SUtils.deserializePrincipal(triggeringPrincipal);
-    this._assert(triggeringPrincipal, "Unable to deserialize passed triggering principal", new Error().lineNumber);
-    if (!triggeringPrincipal) {
-      triggeringPrincipal = Services.scriptSecurityManager.getSystemPrincipal({});
-    }
+
+    triggeringPrincipal = E10SUtils.deserializePrincipal(triggeringPrincipal, () => {
+      this._assert(false, "Unable to deserialize passed triggering principal", new Error().lineNumber);
+      return Services.scriptSecurityManager.getSystemPrincipal({});
+    });
 
     let loadURIOptions = {
       triggeringPrincipal,

toolkit/modules/E10SUtils.jsm

@@ -329,9 +329,15 @@ var E10SUtils = {
    * @param {String} principal_b64 A base64 encoded serialized principal.
    * @return {nsIPrincipal} A deserialized principal.
    */
-  deserializePrincipal(principal_b64) {
-    if (!principal_b64)
-      return null;
+  deserializePrincipal(principal_b64, fallbackPrincipalCallback = null) {
+    if (!principal_b64) {
+      if (!fallbackPrincipalCallback) {
+        debug("No principal passed to deserializePrincipal and no fallbackPrincipalCallback");
+        return null;
+      }
+
+      return fallbackPrincipalCallback();
+    }
 
     try {
       let principal = serializationHelper.deserializeObject(principal_b64);
@@ -340,7 +346,11 @@ var E10SUtils = {
     } catch (e) {
       debug(`Failed to deserialize principal_b64 '${principal_b64}' ${e}`);
     }
-    return null;
+    if (!fallbackPrincipalCallback) {
+      debug("No principal passed to deserializePrincipal and no fallbackPrincipalCallback");
+      return null;
+    }
+    return fallbackPrincipalCallback();
   },
 
   shouldLoadURIInBrowser(browser, uri, multiProcess = true,

toolkit/modules/sessionstore/SessionHistory.jsm

@@ -450,13 +450,12 @@ var SessionHistoryInternal = {
     }
 
     if (entry.triggeringPrincipal_base64) {
-      shEntry.triggeringPrincipal = E10SUtils.deserializePrincipal(entry.triggeringPrincipal_base64);
-    }
-    // Ensure that we have a null principal if we couldn't deserialize it.
-    // This won't always work however is safe to use.
-    if (!shEntry.triggeringPrincipal) {
-      debug("Couldn't deserialize the triggeringPrincipal, falling back to NullPrincipal");
-      shEntry.triggeringPrincipal = Services.scriptSecurityManager.createNullPrincipal({});
+      shEntry.triggeringPrincipal = E10SUtils.deserializePrincipal(entry.triggeringPrincipal_base64, () => {
+        // Ensure that we have a null principal if we couldn't deserialize it.
+        // This won't always work however is safe to use.
+        debug("Couldn't deserialize the triggeringPrincipal, falling back to NullPrincipal");
+        return Services.scriptSecurityManager.createNullPrincipal({});
+      });
     }
     if (entry.principalToInherit_base64) {
       shEntry.principalToInherit = E10SUtils.deserializePrincipal(entry.principalToInherit_base64);