In order to simplify m-c code, move some in pdf.js

* move set/clear|Timeout/Interval and crackURL code in pdf.js
 * remove the "backdoor" in the proxy (used to dispatch event) and so return the dispatch function in the initializer
 * remove listeners if an error occured during sandbox initialization
 * add support for alert and prompt in the sandbox
 * add a function to eval in the global scope

web/app.js

@@ -19,7 +19,6 @@ import {
   AutoPrintRegExp,
   DEFAULT_SCALE_VALUE,
   EventBus,
-  generateRandomStringForSandbox,
   getActiveOrFocusedElement,
   getPDFFileNameFromURL,
   isValidRotation,
@@ -1483,10 +1482,6 @@ const PDFViewerApplication = {
       const { id, command, value } = detail;
       if (!id) {
         switch (command) {
-          case "alert":
-            // eslint-disable-next-line no-alert
-            window.alert(value);
-            break;
           case "clear":
             console.clear();
             break;
@@ -1501,7 +1496,7 @@ const PDFViewerApplication = {
             return;
           case "print":
             this.triggerPrinting();
-            return;
+            break;
           case "println":
             console.log(value);
             break;
@@ -1511,7 +1506,7 @@ const PDFViewerApplication = {
             } else {
               this.pdfViewer.currentScale = value;
             }
-            return;
+            break;
         }
         return;
       }
@@ -1551,8 +1546,6 @@ const PDFViewerApplication = {
     window.addEventListener("mouseup", mouseUp);
     this._scriptingInstance.events.set("mouseup", mouseUp);
 
-    const dispatchEventName = generateRandomStringForSandbox(objects);
-
     if (!this._contentLength) {
       // Always waiting for the entire PDF document to be loaded will, most
       // likely, delay sandbox-creation too much in the general case for all
@@ -1569,24 +1562,28 @@ const PDFViewerApplication = {
     const filename =
       this._contentDispositionFilename || getPDFFileNameFromURL(this.url);
 
-    scripting.createSandbox({
-      objects,
-      dispatchEventName,
-      calculationOrder,
-      appInfo: {
-        platform: navigator.platform,
-        language: navigator.language,
-      },
-      docInfo: {
-        ...this.documentInfo,
-        baseURL: this.baseUrl,
-        filesize: this._contentLength,
-        filename,
-        metadata: this.metadata,
-        numPages: pdfDocument.numPages,
-        URL: this.url,
-      },
-    });
+    try {
+      await scripting.createSandbox({
+        objects,
+        calculationOrder,
+        appInfo: {
+          platform: navigator.platform,
+          language: navigator.language,
+        },
+        docInfo: {
+          ...this.documentInfo,
+          baseURL: this.baseUrl,
+          filesize: this._contentLength,
+          filename,
+          metadata: this.metadata,
+          numPages: pdfDocument.numPages,
+          URL: this.url,
+        },
+      });
+    } catch (error) {
+      console.error(error);
+      this._destroyScriptingInstance();
+    }
   },
 
   /**

web/firefoxcom.js

@@ -256,15 +256,21 @@ class FirefoxComDataRangeTransport extends PDFDataRangeTransport {
 
 class FirefoxScripting {
   static createSandbox(data) {
-    FirefoxCom.requestSync("createSandbox", data);
+    return new Promise(resolve => {
+      FirefoxCom.request("createSandbox", data, resolve);
+    }).then(success => {
+      if (!success) {
+        throw new Error("Cannot start sandbox");
+      }
+    });
   }
 
-  static dispatchEventInSandbox(event) {
-    FirefoxCom.requestSync("dispatchEventInSandbox", event);
+  static async dispatchEventInSandbox(event) {
+    FirefoxCom.request("dispatchEventInSandbox", event);
   }
 
-  static destroySandbox() {
-    FirefoxCom.requestSync("destroySandbox", null);
+  static async destroySandbox() {
+    FirefoxCom.request("destroySandbox", null);
   }
 }
 

web/ui_utils.js

@@ -1015,42 +1015,6 @@ function getActiveOrFocusedElement() {
   return curActiveOrFocused;
 }
 
-/**
- * Generate a random string which is not define somewhere in actions.
- *
- * @param {Object} objects - The value returned by `getFieldObjects` in the API.
- * @returns {string} A unique string.
- */
-function generateRandomStringForSandbox(objects) {
-  const allObjects = Object.values(objects).flat(2);
-  const actions = allObjects
-    .filter(obj => !!obj.actions)
-    .map(obj => Object.values(obj.actions))
-    .flat(2);
-
-  while (true) {
-    const name = new Uint8Array(64);
-    if (typeof crypto !== "undefined") {
-      crypto.getRandomValues(name);
-    } else {
-      for (let i = 0, ii = name.length; i < ii; i++) {
-        name[i] = Math.floor(256 * Math.random());
-      }
-    }
-
-    const nameString =
-      "_" +
-      btoa(
-        Array.from(name)
-          .map(x => String.fromCharCode(x))
-          .join("")
-      );
-    if (actions.every(action => !action.includes(nameString))) {
-      return nameString;
-    }
-  }
-}
-
 export {
   AutoPrintRegExp,
   CSS_UNITS,
@@ -1074,7 +1038,6 @@ export {
   NullL10n,
   EventBus,
   ProgressBar,
-  generateRandomStringForSandbox,
   getPDFFileNameFromURL,
   noContextMenuHandler,
   parseQueryString,