Bug 622760: log exceptions thrown in _onProgress callbacks. r=philiKON

services/sync/modules/resource.js

@@ -452,9 +452,24 @@ ChannelListener.prototype = {
     let siStream = Cc["@mozilla.org/scriptableinputstream;1"].
       createInstance(Ci.nsIScriptableInputStream);
     siStream.init(stream);
-
-    this._data += siStream.read(count);
-    this._onProgress();
+    try {
+      this._data += siStream.read(count);
+    } catch (ex) {
+      this._log.warn("Exception thrown reading " + count +
+                     " bytes from " + siStream + ".");
+      throw ex;
+    }
+    
+    try {
+      this._onProgress();
+    } catch (ex) {
+      this._log.warn("Got exception calling onProgress handler during fetch of "
+                     + req.URI.spec);
+      this._log.debug(Utils.stackTrace(ex));
+      this._log.trace("Rethrowing; expect a failure code from the HTTP channel.");
+      throw ex;
+    }
+    
     this.delayAbort();
   },
 

services/sync/tests/unit/test_resource.js

@@ -472,5 +472,51 @@ function run_test() {
   do_check_eq(content.status, 0);
   do_check_false(content.success);
 
+  _("Checking handling of errors in onProgress.");
+  let res18 = new Resource("http://localhost:8080/json");
+  let onProgress = function(rec) {
+    // Provoke an XPC exception without a Javascript wrapper.
+    Svc.IO.newURI("::::::::", null, null);
+  };
+  res18._onProgress = onProgress;
+  let oldWarn = res18._log.warn;
+  let warnings = [];
+  res18._log.warn = function(msg) { warnings.push(msg) };
+  error = undefined;
+  try {
+    content = res18.get();
+  } catch (ex) {
+    error = ex;
+  }
+
+  // It throws and logs.
+  do_check_eq(error, "Error: NS_ERROR_MALFORMED_URI");
+  do_check_eq(warnings.pop(),
+              "Got exception calling onProgress handler during fetch of " +
+              "http://localhost:8080/json");
+  
+  // And this is what happens if JS throws an exception.
+  res18 = new Resource("http://localhost:8080/json");
+  onProgress = function(rec) {
+    throw "BOO!";
+  };
+  res18._onProgress = onProgress;
+  oldWarn = res18._log.warn;
+  warnings = [];
+  res18._log.warn = function(msg) { warnings.push(msg) };
+  error = undefined;
+  try {
+    content = res18.get();
+  } catch (ex) {
+    error = ex;
+  }
+
+  // It throws and logs.
+  do_check_eq(error, "Error: NS_ERROR_XPC_JS_THREW_STRING");
+  do_check_eq(warnings.pop(),
+              "Got exception calling onProgress handler during fetch of " +
+              "http://localhost:8080/json");
+  
+  
   server.stop(do_test_finished);
 }

services/sync/tests/unit/test_resource_async.js

@@ -619,6 +619,49 @@ function run_test() {
       next();
     }));
 
+  }, function (next) {
+
+    _("Exception handling inside fetches.");
+    let res14 = new AsyncResource("http://localhost:8080/json");
+    res14._onProgress = function(rec) {
+      // Provoke an XPC exception without a Javascript wrapper.
+      Svc.IO.newURI("::::::::", null, null);
+    };
+    let warnings = [];
+    res14._log.warn = function(msg) { warnings.push(msg) };
+
+    res14.get(ensureThrows(function (error, content) {
+      do_check_eq(error, "Error: NS_ERROR_MALFORMED_URI");
+      do_check_eq(content, null);
+      do_check_eq(warnings.pop(),
+                  "Got exception calling onProgress handler during fetch of " +
+                  "http://localhost:8080/json");
+      
+      do_test_finished();
+      next();
+    }));
+
+  }, function (next) {
+
+    _("JS exception handling inside fetches.");
+    let res15 = new AsyncResource("http://localhost:8080/json");
+    res15._onProgress = function(rec) {
+      throw "BOO!";
+    };
+    warnings = [];
+    res15._log.warn = function(msg) { warnings.push(msg) };
+
+    res15.get(ensureThrows(function (error, content) {
+      do_check_eq(error, "Error: NS_ERROR_XPC_JS_THREW_STRING");
+      do_check_eq(content, null);
+      do_check_eq(warnings.pop(),
+                  "Got exception calling onProgress handler during fetch of " +
+                  "http://localhost:8080/json");
+      
+      do_test_finished();
+      next();
+    }));
+
   }, function (next) {
 
     // Don't quit test harness before server shuts down.