Bug 897751 - Tab close button's DoubleClick protection handler leaks. r=mano

browser/base/content/tabbrowser.xml

@@ -4115,6 +4115,61 @@
         event.preventDefault();
       ]]></handler>
 
+      <handler event="click" button="0" phase="capturing"><![CDATA[
+        /* Catches extra clicks meant for the in-tab close button.
+         * Placed here to avoid leaking (a temporary handler added from the
+         * in-tab close button binding would close over the tab and leak it
+         * until the handler itself was removed). (bug 897751)
+         *
+         * The only sequence in which a second click event (i.e. dblclik)
+         * can be dispatched on an in-tab close button is when it is shown
+         * after the first click (i.e. the first click event was dispatched
+         * on the tab). This happens when we show the close button only on
+         * the active tab. (bug 352021)
+         * The only sequence in which a third click event can be dispatched
+         * on an in-tab close button is when the tab was opened with a
+         * double click on the tabbar. (bug 378344)
+         * In both cases, it is most likely that the close button area has
+         * been accidentally clicked, therefore we do not close the tab.
+         *
+         * We don't want to ignore processing of more than one click event,
+         * though, since the user might actually be repeatedly clicking to
+         * close many tabs at once.
+         */
+        let target = event.originalTarget;
+        if (target.className == 'tab-close-button') {
+          // We preemptively set this to allow the closing-multiple-tabs-
+          // in-a-row case.
+          if (this._blockDblClick) {
+            target._ignoredCloseButtonClicks = true;
+          } else if (event.detail > 1 && !target._ignoredCloseButtonClicks) {
+            target._ignoredCloseButtonClicks = true;
+            event.stopPropagation();
+            return;
+          } else {
+            // Reset the "ignored click" flag
+            target._ignoredCloseButtonClicks = false;
+          }
+        }
+
+        /* Protects from close-tab-button errant doubleclick:
+         * Since we're removing the event target, if the user
+         * double-clicks the button, the dblclick event will be dispatched
+         * with the tabbar as its event target (and explicit/originalTarget),
+         * which treats that as a mouse gesture for opening a new tab.
+         * In this context, we're manually blocking the dblclick event
+         * (see tabbrowser-close-tab-button dblclick handler).
+         */
+        if (this._blockDblClick) {
+          if (!("_clickedTabBarOnce" in this)) {
+            this._clickedTabBarOnce = true;
+            return;
+          }
+          delete this._clickedTabBarOnce;
+          this._blockDblClick = false;
+        }
+      ]]></handler>
+
       <handler event="click"><![CDATA[
         if (event.button != 1)
           return;
@@ -4494,53 +4549,10 @@
       <handler event="click" button="0"><![CDATA[
         var bindingParent = document.getBindingParent(this);
         var tabContainer = bindingParent.parentNode;
-        /* The only sequence in which a second click event (i.e. dblclik)
-         * can be dispatched on an in-tab close button is when it is shown
-         * after the first click (i.e. the first click event was dispatched
-         * on the tab). This happens when we show the close button only on
-         * the active tab. (bug 352021)
-         * The only sequence in which a third click event can be dispatched
-         * on an in-tab close button is when the tab was opened with a
-         * double click on the tabbar. (bug 378344)
-         * In both cases, it is most likely that the close button area has
-         * been accidentally clicked, therefore we do not close the tab.
-         *
-         * We don't want to ignore processing of more than one click event,
-         * though, since the user might actually be repeatedly clicking to
-         * close many tabs at once.
-         */
-        if (event.detail > 1 && !this._ignoredClick) {
-          this._ignoredClick = true;
-          return;
-        }
-
-        // Reset the "ignored click" flag
-        this._ignoredClick = false;
-
         tabContainer.tabbrowser.removeTab(bindingParent, {animate: true, byMouse: true});
+        // This enables double-click protection for the tab container
+        // (see tabbrowser-tabs 'click' handler).
         tabContainer._blockDblClick = true;
-
-        /* XXXmano hack (see bug 343628):
-         * Since we're removing the event target, if the user
-         * double-clicks this button, the dblclick event will be dispatched
-         * with the tabbar as its event target (and explicit/originalTarget),
-         * which treats that as a mouse gesture for opening a new tab.
-         * In this context, we're manually blocking the dblclick event
-         * (see dblclick handler).
-         */
-        var clickedOnce = false;
-        function enableDblClick(event) {
-          var target = event.originalTarget;
-          if (target.className == 'tab-close-button')
-            target._ignoredClick = true;
-          if (!clickedOnce) {
-            clickedOnce = true;
-            return;
-          }
-          tabContainer._blockDblClick = false;
-          tabContainer.removeEventListener("click", enableDblClick, true);
-        }
-        tabContainer.addEventListener("click", enableDblClick, true);
       ]]></handler>
 
       <handler event="dblclick" button="0" phase="capturing">