--- mozilla-1.9.1_original/widget/src/gtk2/nsWindow.cpp	Tue Nov 17 15:05:27 2009
+++ mozilla-1.9.1/widget/src/gtk2/nsWindow.cpp	Wed Nov 18 11:51:07 2009
@@ -2859,7 +2859,56 @@ nsWindow::InitButtonEvent(nsMouseEvent &aEvent,
     }
 }
 
+/* the values are gdk button numbers */
+/* first entry unused; this is to accomodate for gdk numbering buttons from 1; */
+static PRUint16 mouse_button_map[10];
+static PRUint16 context_menu_button = 3;
+
 void
+set_default_button_map(void) {
+    int i;
+
+    for (i = 0; i < 10; ++i)
+       mouse_button_map[i] = i;
+}
+
+/* format example:
+  "x3m2"
+  will map:
+    LMB -> to what it is by default, i.e. left mouse button =)
+    MMB -> RMB and also make it the context menu button
+    RMB -> MMB
+*/ 
+void
+update_mouse_button_map(const char *cstr) {
+    nsAutoString str;
+    const PRUnichar *p, *end;
+    int i, val;
+
+    set_default_button_map();
+
+    if (!cstr)
+        return;
+
+    str.AssignWithConversion(cstr);
+    p = str.BeginReading();
+    end = str.EndReading();
+    for (i = 1; p < end && i < 10; ++i, ++p) {
+        if (*p == PRUnichar('m')) {
+            --i;
+            if (i < 1)
+                continue;
+            context_menu_button = i;
+            continue;
+        }
+        val = *p - PRUnichar('0');
+        if (val < 1 || val > 9)
+            continue;
+        mouse_button_map[i] = val;
+    }
+}
+
+void
 nsWindow::OnButtonPressEvent(GtkWidget *aWidget, GdkEventButton *aEvent)
 {
     nsEventStatus status;
@@ -2894,8 +2943,9 @@ nsWindow::OnButtonPressEvent(GtkWidget *aWidget, GdkEv
     if (gConsumeRollupEvent && rolledUp)
             return;
 
+    PRUint16 Button = (aEvent->button > 0 && aEvent->button <= 9) ? mouse_button_map[aEvent->button] : 0;
     PRUint16 domButton;
-    switch (aEvent->button) {
+    switch (Button) {
     case 1:
         domButton = nsMouseEvent::eLeftButton;
         break;
@@ -2944,7 +2994,7 @@ nsWindow::OnButtonPressEvent(GtkWidget *aWidget, GdkEv
     DispatchEvent(&event, status);
 
     // right menu click on linux should also pop up a context menu
-    if (domButton == nsMouseEvent::eRightButton &&
+    if (aEvent->button == context_menu_button &&
         NS_LIKELY(!mIsDestroyed)) {
         nsMouseEvent contextMenuEvent(PR_TRUE, NS_CONTEXTMENU, this,
                                       nsMouseEvent::eReal);
@@ -2956,10 +3006,11 @@ nsWindow::OnButtonPressEvent(GtkWidget *aWidget, GdkEv
 void
 nsWindow::OnButtonReleaseEvent(GtkWidget *aWidget, GdkEventButton *aEvent)
 {
+    PRUint16 Button = (aEvent->button > 0 && aEvent->button <= 9) ? mouse_button_map[aEvent->button] : 0;
     PRUint16 domButton;
     mLastButtonReleaseTime = aEvent->time;
 
-    switch (aEvent->button) {
+    switch (Button) {
     case 1:
         domButton = nsMouseEvent::eLeftButton;
         break;
@@ -5882,6 +5933,7 @@ drag_data_received_event_cb(GtkWidget *aWidget,
                                     aInfo, aTime, aData);
 }
 
+
 /* static */
 nsresult
 initialize_prefs(void)
@@ -5892,6 +5944,7 @@ initialize_prefs(void)
 
     PRBool val = PR_TRUE;
     nsresult rv;
+    char *s;
 
     rv = prefs->GetBoolPref("mozilla.widget.raise-on-setfocus", &val);
     if (NS_SUCCEEDED(rv))
@@ -5908,6 +5961,10 @@ initialize_prefs(void)
     rv = prefs->GetBoolPref("mozilla.widget.disable-native-theme", &val);
     if (NS_SUCCEEDED(rv))
         gDisableNativeTheme = val;
+
+    rv = prefs->GetCharPref("mozilla.widget.mouse-button-map", &s);
+    if (NS_SUCCEEDED(rv))
+        update_mouse_button_map(s);
 
     return NS_OK;
 }
--- mozilla-1.9.1_original/browser/app/profile/firefox.js	Tue Nov 17 15:05:36 2009
+++ mozilla-1.9.1/browser/app/profile/firefox.js	Wed Nov 18 11:09:31 2009
@@ -843,3 +843,5 @@ pref("browser.privatebrowsing.dont_prompt_on_enter", f
 // base url for the wifi geolocation network provider
 pref("geo.wifi.uri", "https://www.google.com/loc/json");
 
+// mouse button map
+pref("mozilla.widget.mouse-button-map", "123m");