Don't use modes.clear() to clear the last message and some collateral fixes.

common/content/browser.js

@@ -188,9 +188,7 @@ const Browser = Module("browser", {
             function () {
                 window.QueryInterface(Ci.nsIInterfaceRequestor)
                       .getInterface(Ci.nsIDOMWindowUtils).redraw();
-                commandline.widgets.message = null;
+                commandline.clear();
-                if (modes.main != modes.COMMAND_LINE)
-                    commandline.widgets.command = null;
             },
             { argCount: "0" });
     }

common/content/buffer.js

@@ -161,7 +161,7 @@ const Buffer = Module("buffer", {
     // called when the active document is scrolled
     _updateBufferPosition: function _updateBufferPosition() {
         statusline.updateBufferPosition();
-        modes.show(); // Clear the status line.
+        commandline.clear();
     },
 
     onDOMContentLoaded: function onDOMContentLoaded(event) {
@@ -273,7 +273,7 @@ const Buffer = Module("buffer", {
             util.timeout(function () {
                 statusline.updateBufferPosition();
                 statusline.updateZoomLevel();
-                modes.show(); // Clear the status line.
+                commandline.clear();
             }, 500);
         },
         // called at the very end of a page load
@@ -295,7 +295,7 @@ const Buffer = Module("buffer", {
                 if (ssli == 1)
                     statusline.updateUrl();
                 else if (ssli == 2)
-                    modes.show();
+                    commandline.clear();
             }
         },
     }),

common/content/commandline.js

@@ -404,6 +404,7 @@ const CommandLine = Module("commandline", {
         win.focus();
 
         this._startHints = false;
+        if (!(modes.extended & modes.OUTPUT_MULTILINE))
             modes.set(modes.COMMAND_LINE, modes.OUTPUT_MULTILINE);
         commandline.updateMorePrompt();
     },
@@ -567,6 +568,13 @@ const CommandLine = Module("commandline", {
         return this._lastCommand = val;
     },
 
+    clear: function () {
+        if (this.widgets.message && this.widgets.message[1] === this._lastClearable)
+            this.widgets.message = null;
+        if (modes.main != modes.COMMAND_LINE)
+            this.widgets.command = null;
+    },
+
     /**
      * Displays the multi-line output of a command, preceded by the last
      * executed ex command string.
@@ -638,21 +646,19 @@ const CommandLine = Module("commandline", {
             if (this.widgets.message && this.widgets.message[1] == this._lastEcho)
                 this._echoMultiline(<span highlight="Message">{this._lastEcho}</span>,
                                     this.widgets.message[0]);
-            this._lastEcho = (action == this._echoLine) && str;
-        }
-
-        // TODO: this is all a bit convoluted - clean up.
-        // assume that FORCE_MULTILINE output is fully styled
-        if (!(flags & this.FORCE_MULTILINE) && !single
-            && (!this.widgets.mowContainer.collapsed || this.widgets.message && this.widgets.message[1] == this._lastEcho)) {
 
+            if (!(flags & this.FORCE_MULTILINE) && !this.widgets.mowContainer.collapsed) {
                 highlightGroup += " Message";
                 action = this._echoMultiline;
             }
+            this._lastEcho = (action == this._echoLine) && str;
+        }
 
         if ((flags & this.FORCE_MULTILINE) || (/\n/.test(str) || typeof str == "xml") && !(flags & this.FORCE_SINGLELINE))
             action = this._echoMultiline;
 
+        this._lastClearable = action === this._echoLine && String(str);
+
         if (action)
             action.call(this, str, highlightGroup, single);
     }),

common/content/events.js

@@ -638,7 +638,7 @@ const Events = Module("events", {
             else
                 dactyl.echo("Waiting for page to load...", commandline.DISALLOW_MULTILINE);
         }
-        modes.show();
+        commandline.clear();
 
         // TODO: allow macros to be continued when page does not fully load with an option
         let ret = (buffer.loaded == 1);