diff --git a/common/content/editor.js b/common/content/editor.js
index 27c0c444..5a31c878 100644
--- a/common/content/editor.js
+++ b/common/content/editor.js
@@ -1161,14 +1161,16 @@ var Editor = Module("editor", XPCOM(Ci.nsIEditActionListener, ModuleBase), {
              "<*-Home>", "<*-End>", "<*-PageUp>", "<*-PageDown>",
              "<M-c>", "<M-v>", "<*-Tab>"],
             "Handled by " + config.host,
-            () => Events.PASS_THROUGH);
+            () => Events.PASS,
+            { passThrough: true });
 
         mappings.add([modes.INSERT],
             ["<Space>", "<Return>"], "Expand Insert mode abbreviation",
             function () {
                 editor.expandAbbreviation(modes.INSERT);
-                return Events.PASS_THROUGH;
-            });
+                return Events.PASS;
+            },
+            { passThrough: true });
 
         mappings.add([modes.INSERT],
             ["<C-]>", "<C-5>"], "Expand Insert mode abbreviation",
diff --git a/common/content/events.js b/common/content/events.js
index b4d94edb..05bcc157 100644
--- a/common/content/events.js
+++ b/common/content/events.js
@@ -784,21 +784,43 @@ var Events = Module("events", {
 
             let key = DOM.Event.stringify(event);
 
-            let pass = this.passing && !event.isMacro ||
-                    DOM.Event.feedingEvent && DOM.Event.feedingEvent.isReplay ||
-                    event.isReplay ||
-                    modes.main == modes.PASS_THROUGH ||
-                    modes.main == modes.QUOTE
-                        && modes.getStack(1).main !== modes.PASS_THROUGH
-                        && !this.shouldPass(event) ||
-                    !modes.passThrough && this.shouldPass(event) ||
-                    !this.processor && event.type === "keydown"
-                        && options.get("passunknown").getKey(modes.main.allBases)
-                        && !(modes.main.count && /^\d$/.test(key) ||
-                             modes.main.allBases.some(
-                               mode => mappings.hives
-                                               .some(hive => hive.get(mode, key)
-                                                          || hive.getCandidates(mode, key))));
+            let hasCandidates = mode => {
+                return mappings.hives.some(hive => (hive.get(mode, key, true) ||
+                                                    hive.getCandidates(mode, key, true)));
+            };
+
+            let pass = (() => {
+                if (this.passing && !event.isMacro)
+                    return true;
+
+                if (DOM.Event.feedingEvent && DOM.Event.feedingEvent.isReplay)
+                    return true;
+
+                if (event.isReplay)
+                    return true;
+
+                if (modes.main == modes.PASS_THROUGH)
+                    return true;
+
+                if (modes.main == modes.QUOTE &&
+                        modes.getStack(1).main !== modes.PASS_THROUGH &&
+                        !this.shouldPass(event))
+                    return true;
+
+                if (!modes.passThrough && this.shouldPass(event))
+                    return true;
+
+                if (!this.processor && event.type === "keydown" &&
+                        options.get("passunknown").getKey(modes.main.allBases)) {
+                    if (!(modes.main.count && /^\d$/.test(key)))
+                        return true;
+
+                    if (modes.main.allBases.some(hasCandidates))
+                        return true;
+                }
+
+                return false;
+            })();
 
             events.dbg("ON " + event.type.toUpperCase() + " " + key +
                        " passing: " + this.passing + " " +
diff --git a/common/content/mappings.js b/common/content/mappings.js
index 00bb4a77..d7fe8b38 100644
--- a/common/content/mappings.js
+++ b/common/content/mappings.js
@@ -84,6 +84,8 @@ var Map = Class("Map", {
     /** @property {boolean} Whether the RHS of the mapping should expand mappings recursively. */
     noremap: false,
 
+    passThrough: true,
+
     /** @property {function(object)} A function to be executed before this mapping. */
     preExecute: function preExecute(args) {},
     /** @property {function(object)} A function to be executed after this mapping. */
@@ -232,10 +234,13 @@ var MapHive = Class("MapHive", Contexts.Hive, {
      *
      * @param {Modes.Mode} mode The mode to search.
      * @param {string} cmd The map name to match.
+     * @param {boolean} skipPassThrough Ignore pass-through mappings.
      * @returns {Map|null}
      */
-    get: function (mode, cmd) {
-        return this.getStack(mode).mappings[cmd];
+    get: function (mode, cmd, skipPassThrough = false) {
+        let map = this.getStack(mode).mappings[cmd];
+        if (!(skipPassThrough && map.passThrough))
+            return map;
     },
 
     /**
@@ -244,9 +249,12 @@ var MapHive = Class("MapHive", Contexts.Hive, {
      *
      * @param {Modes.Mode} mode The mode to search.
      * @param {string} prefix The map prefix string to match.
+     * @param {boolean} skipPassThrough Ignore pass-through mappings.
      * @returns {number)
      */
-    getCandidates: function (mode, prefix) {
+    getCandidates: function (mode, prefix, skipPassThrough = false) {
+        if (skipPassThrough)
+            return this.getStack(mode).hardCandidates[prefix] || 0;
         return this.getStack(mode).candidates[prefix] || 0;
     },
 
@@ -294,9 +302,8 @@ var MapHive = Class("MapHive", Contexts.Hive, {
 }, {
     Stack: Class("Stack", Array, {
         init: function (ary) {
-            let self = ary || [];
-            self.__proto__ = this.__proto__;
-            return self;
+            if (ary)
+                this.push(...ary);
         },
 
         "@@iterator": function () {
@@ -304,6 +311,7 @@ var MapHive = Class("MapHive", Contexts.Hive, {
         },
 
         get candidates() { return this.states.candidates; },
+        get hardCandidates() { return this.states.hardCandidates; },
         get mappings() { return this.states.mappings; },
 
         add: function (map) {
@@ -312,8 +320,9 @@ var MapHive = Class("MapHive", Contexts.Hive, {
         },
 
         states: Class.Memoize(function () {
-            var states = {
+            let states = {
                 candidates: {},
+                hardCandidates: {},
                 mappings: {}
             };
 
@@ -323,8 +332,11 @@ var MapHive = Class("MapHive", Contexts.Hive, {
                     let state = "";
                     for (let key of DOM.Event.iterKeys(name)) {
                         state += key;
-                        if (state !== name)
+                        if (state !== name) {
                             states.candidates[state] = (states.candidates[state] || 0) + 1;
+                            if (!map.passThrough)
+                                states.hardCandidates[state] = (states.hardCandidates[state] || 0) + 1;
+                        }
                     }
                 }
             return states;