This patch includes fixes for bug 297121 "many timer messages in javascript console",

and it also includes the following fixes:
 - make binaryToHex work for octets < 0x10
 - make selectUpdate return non-null
 - no need for "map" variable in _verifyDownload

toolkit/mozapps/update/src/nsUpdateService.js.in

@@ -47,6 +47,7 @@ const PREF_APP_UPDATE_AUTOINSTALL_ENABLED = "app.update.autoInstallEnabled";
 const PREF_APP_UPDATE_AUTOINSTALL_MODE    = "app.update.autoInstallMode";
 const PREF_APP_UPDATE_INTERVAL            = "app.update.interval";
 const PREF_APP_UPDATE_TIMER               = "app.update.timer";
+const PREF_APP_UPDATE_LOG_ENABLED         = "app.update.logEnabled";
 
 const PREF_APP_UPDATE_URL                 = "app.update.url";
 
@@ -92,10 +93,11 @@ const nsICryptoHash           = Components.interfaces.nsICryptoHash;
 
 const Node = Components.interfaces.nsIDOMNode;
 
-var gApp      = null;
-var gPref     = null;
-var gOS       = null;
-var gConsole  = null;
+var gApp        = null;
+var gPref       = null;
+var gOS         = null;
+var gConsole    = null;
+var gLogEnabled = false;
 
 /**
  * Logs a string to the error console. 
@@ -103,8 +105,10 @@ var gConsole  = null;
  *          The string to write to the error console..
  */  
 function LOG(string) {
-  // dump("*** " + string + "\n");
-  gConsole.logStringMessage(string);
+  if (gLogEnabled) {
+    dump("*** " + string + "\n");
+    gConsole.logStringMessage(string);
+  }
 }
 
 /**
@@ -113,7 +117,10 @@ function LOG(string) {
 function binaryToHex(input) {
   var result = "";
   for (var i = 0; i < input.length; ++i) {
-    result += input.charCodeAt(i).toString(16);
+    var hex = input.charCodeAt(i).toString(16);
+    if (hex.length == 1)
+      hex = "0" + hex;
+    result += hex;
   }
   return result;
 }
@@ -368,6 +375,8 @@ function UpdateService() {
   // Observe xpcom-shutdown to unhook pref branch observers above to avoid 
   // shutdown leaks.
   gOS.addObserver(this, "xpcom-shutdown", false);
+
+  gLogEnabled = getPref("getBoolPref", PREF_APP_UPDATE_LOG_ENABLED, false);
 }
 
 UpdateService.prototype = {
@@ -487,17 +496,17 @@ UpdateService.prototype = {
     // Choose the newest of the available minor and major updates. 
     var majorUpdate = null, minorUpdate = null;
     var newestMinor = updates[0], newestMajor = updates[0];
-    
+
     var vc = new VersionChecker();
     for (var i = 0; i < updates.length; ++i) {
       if (updates[i].type == "major" && 
-          vc.compare(newestMajor.version, updates[i].version) < 0)
+          vc.compare(newestMajor.version, updates[i].version) <= 0)
         majorUpdate = newestMajor = updates[i];
       if (updates[i].type == "minor" && 
-          vc.compare(newestMinor.version, updates[i].version) < 0)
+          vc.compare(newestMinor.version, updates[i].version) <= 0)
         minorUpdate = newestMinor = updates[i];
     }
-    
+
     // If there's a major update, always try and fetch that one first, 
     // otherwise fall back to the newest minor update.
     return majorUpdate || minorUpdate;
@@ -890,19 +899,15 @@ Downloader.prototype = {
     try {
       var hash = Components.classes["@mozilla.org/security/hash;1"].
           createInstance(nsICryptoHash);
-      const map = {
-        "MD2"    : nsICryptoHash.MD2,
-        "MD5"    : nsICryptoHash.MD5,
-        "SHA1"   : nsICryptoHash.SHA1,
-        "SHA256" : nsICryptoHash.SHA256,
-        "SHA384" : nsICryptoHash.SHA384,
-        "SHA512" : nsICryptoHash.SHA512
-      };
-      var hashfunction = this._patch.hashfunction.toUpperCase();
-      if (!(hashfunction in map))
+      var hashfunction = nsICryptoHash[this._patch.hashfunction.toUpperCase()];
+      if (hashfunction == undefined)
         return false;
-      hash.init(map[hashfunction]);
+      hash.init(hashfunction);
       hash.updateFromStream(fileStream, -1);
+      // NOTE: For now, we assume that the format of _patch.hashvalue is hex
+      // encoded binary (such as what is typically output by programs like
+      // sha1sum).  In the future, this may change to base64 depending on how
+      // we choose to compute these hashes.
       digest = binaryToHex(hash.finish(false));
     } catch (e) {
       LOG("failed to compute hash of downloaded update archive");
@@ -911,7 +916,7 @@ Downloader.prototype = {
 
     fileStream.close();
 
-    return digest == this._patch.hashvalue;
+    return digest == this._patch.hashvalue.toLowerCase();
   },
 
   /**