Prevent multiple lock requests from being executed (bug 441922, r=thunder)

services/sync/modules/async.js

@@ -192,6 +192,8 @@ Generator.prototype = {
 
       this._exception = e;
 
+    } else if (e.message && e.message == 'Cannot acquire lock (internal lock)') {
+      this._log.warn("Exception: " + Utils.exceptionStr(e));
     } else {
       this._log.error("Exception: " + Utils.exceptionStr(e));
       this._log.debug("Stack trace:\n" + Utils.stackTrace(e));

services/sync/modules/dav.js

@@ -252,9 +252,6 @@ DAVCollection.prototype = {
   },
 
   LOCK: function DC_LOCK(path, data, onComplete) {
-    if (!this._lockAllowed)
-      throw "Cannot acquire lock (internal lock)";
-
     let headers = {'Content-type': 'text/xml; charset="utf-8"',
                    'Depth': 'infinity',
                    'Timeout': 'Second-600'};
@@ -364,6 +361,9 @@ DAVCollection.prototype = {
     let self = yield;
 
     this._log.trace("Acquiring lock");
+    if (!this._lockAllowed)
+      throw {message: "Cannot acquire lock (internal lock)"};
+    this._lockAllowed = false;
 
     if (DAVLocks['default']) {
       this._log.debug("Lock called, but we already hold a token");
@@ -379,8 +379,10 @@ DAVCollection.prototype = {
               "</D:lockinfo>", self.cb);
     let resp = yield;
 
-    if (resp.status < 200 || resp.status >= 300)
+    if (resp.status < 200 || resp.status >= 300) {
+      this._lockAllowed = true;
       return;
+    }
 
     let tokens = Utils.xpath(resp.responseXML, '//D:locktoken/D:href');
     let token = tokens.iterateNext();
@@ -393,11 +395,14 @@ DAVCollection.prototype = {
 
     if (!DAVLocks['default']) {
       this._log.warn("Could not acquire lock");
+      this._lockAllowed = true;
       self.done();
       return;
     }
 
     this._log.trace("Lock acquired");
+    this._lockAllowed = true;
+    
     self.done(DAVLocks['default']);
   },
 

services/sync/modules/util.js

@@ -203,7 +203,7 @@ let Utils = {
   },
 
   exceptionStr: function Weave_exceptionStr(e) {
-    let message = e.message? e.message : e;
+    let message = e.message ? e.message : e;
     let location = "";
 
     if (e.location)