diff --git a/mozilla/extensions/irc/js/lib/irc.js b/mozilla/extensions/irc/js/lib/irc.js
index bf2861b190f..17bbca3793d 100644
--- a/mozilla/extensions/irc/js/lib/irc.js
+++ b/mozilla/extensions/irc/js/lib/irc.js
@@ -488,6 +488,7 @@ function CIRCServer (parent, hostname, port, isSecure, password)
     s.supports = null;
     s.channelTypes = null;
     s.channelModes = null;
+    s.channelCount = -1;
     s.userModes = null;
     s.maxLineLength = 400;
 
@@ -1588,6 +1589,15 @@ function serv_251(e)
     e.set = "network";
 }
 
+/* channels */
+CIRCServer.prototype.on254 =
+function serv_254(e)
+{
+    this.channelCount = e.params[2];
+    e.destObject = this.parent;
+    e.set = "network";
+}
+
 /* user away message */
 CIRCServer.prototype.on301 =
 function serv_301(e)
diff --git a/mozilla/extensions/irc/locales/en-US/chrome/chatzilla.properties b/mozilla/extensions/irc/locales/en-US/chrome/chatzilla.properties
index 77e477c85ed..c89e8e83360 100644
--- a/mozilla/extensions/irc/locales/en-US/chrome/chatzilla.properties
+++ b/mozilla/extensions/irc/locales/en-US/chrome/chatzilla.properties
@@ -1181,6 +1181,7 @@ msg.nick.prompt    = Enter a nickname to use:
 
 msg.list.rerouted  = List reply will appear on the ``%S'' view.
 msg.list.end       = Displayed %S of %S channels.
+msg.list.chancount = This server has %S channels. Listing them all will probably take a long time, and may lead to ChatZilla becoming unresponsive or being disconnected by the server. [[List Channels][List all channels][%S]]
 
 msg.who.end        = End of WHO results for ``%S'', %S user(s) found.
 msg.who.match      = User %S, (%S@%S) ``%S'' (%S), member of %S, is connected to <irc://%S/>, %S hop(s).
diff --git a/mozilla/extensions/irc/xul/content/commands.js b/mozilla/extensions/irc/xul/content/commands.js
index 12cafec5a8d..21a0e89660c 100644
--- a/mozilla/extensions/irc/xul/content/commands.js
+++ b/mozilla/extensions/irc/xul/content/commands.js
@@ -2038,7 +2038,19 @@ function cmdMotif(e)
 function cmdList(e)
 {
     if (!e.channelName)
+    {
         e.channelName = "";
+        var c = e.server.channelCount;
+        if ((c > client.SAFE_LIST_COUNT) && !("listWarned" in e.network))
+        {
+            client.munger.getRule(".inline-buttons").enabled = true;
+            display(getMsg(MSG_LIST_CHANCOUNT, [c, "list"]), MT_WARN);
+            client.munger.getRule(".inline-buttons").enabled = false;
+            e.network.listWarned = true;
+            return;
+        }
+    }
+
     e.network.list(e.channelName);
 }
 
@@ -2086,6 +2098,16 @@ function cmdRlist(e)
         display(MSG_ERR_INVALID_REGEX, MT_ERROR);
         return;
     }
+
+    var c = e.server.channelCount;
+    if ((c > client.SAFE_LIST_COUNT) && !("listWarned" in e.network))
+    {
+        client.munger.getRule(".inline-buttons").enabled = true;
+        display(getMsg(MSG_LIST_CHANCOUNT, [c, "rlist " + e.regexp]), MT_WARN);
+        client.munger.getRule(".inline-buttons").enabled = false;
+        e.network.listWarned = true;
+        return;
+    }
     e.network.list(re);
 }
 
diff --git a/mozilla/extensions/irc/xul/content/static.js b/mozilla/extensions/irc/xul/content/static.js
index 083946cf83a..d171ec83b20 100644
--- a/mozilla/extensions/irc/xul/content/static.js
+++ b/mozilla/extensions/irc/xul/content/static.js
@@ -79,10 +79,6 @@ client.MAX_NICK_DISPLAY = 14;
 /* longest word to show in display before abbreviating */
 client.MAX_WORD_DISPLAY = 20;
 
-client.MAX_MSG_PER_ROW = 3; /* default number of messages to collapse into a
-                             * single row, max. */
-client.INITIAL_COLSPAN = 5; /* MAX_MSG_PER_ROW cannot grow to greater than
-                             * one half INITIAL_COLSPAN + 1. */
 client.NOTIFY_TIMEOUT = 5 * 60 * 1000; /* update notify list every 5 minutes */
 
 // Check every minute which networks have away statuses that need an update.
@@ -95,14 +91,13 @@ client.SLOPPY_NETWORKS = true; /* true if msgs from a network can be displayed
                                 * is on the network that the results came from)
                                 */
 client.DOUBLETAB_TIME = 500;
-client.IMAGEDIR = "chrome://chatzilla/skin/images/";
 client.HIDE_CODES = true;      /* true if you'd prefer to show numeric response
                                 * codes as some default value (ie, "===") */
-/* true if the browser widget shouldn't be allowed to take focus.  windows, and
- * probably the mac, need to be able to give focus to the browser widget for
- * copy to work properly. */
-client.NO_BROWSER_FOCUS = (navigator.platform.search(/mac|win/i) == -1);
 client.DEFAULT_RESPONSE_CODE = "===";
+
+/* Maximum number of channels we'll try to list without complaining */
+client.SAFE_LIST_COUNT = 500;
+
 /* Minimum number of users above or below the conference limit the user count
  * must go, before it is changed. This allows the user count to fluctuate
  * around the limit without continously going on and off.