Bug 1115616 - Part 2: Commit composition string forcibly when search suggestion list is clicked in about:home. r=adw

browser/base/content/searchSuggestionUI.js

@@ -240,16 +240,11 @@ SearchSuggestionUIController.prototype = {
 
     // Commit composition string forcibly, because setting input value does not
     // work if input has composition string (see bug 1115616 and bug 632744).
-    try {
-      let imeEditor = this.input.editor.QueryInterface(Components.interfaces.nsIEditorIMESupport);
-      if (imeEditor.composing) {
-        // Ignore input event for compisition end to avoid getting suggestion
-        // again.
-        this._ignoreInputEvent = true;
-        imeEditor.forceCompositionEnd();
-        this._ignoreInputEvent = false;
-      }
-    } catch(e) { }
+    // Ignore input event for composition end to avoid getting suggestion again.
+    this._ignoreInputEvent = true;
+    this.input.blur();
+    this.input.focus();
+    this._ignoreInputEvent = false;
 
     this.input.value = suggestion;
     this.input.setAttribute("selection-index", idx);

browser/base/content/test/general/browser_aboutHome.js

@@ -380,6 +380,56 @@ let gTests = [
     });
   }
 },
+{
+  desc: "Clicking suggestion list while composing",
+  setup: function() {},
+  run: function()
+  {
+    return Task.spawn(function* () {
+      // Start composition and type "x"
+      let input = gBrowser.contentDocument.getElementById("searchText");
+      input.focus();
+      EventUtils.synthesizeComposition({ type: "compositionstart", data: "" });
+      EventUtils.synthesizeComposition({ type: "compositionupdate", data: "x" });
+      EventUtils.synthesizeCompositionChange({
+        composition: {
+          string: "x",
+          clauses: [
+            { length: 1, attr: EventUtils.COMPOSITION_ATTR_RAWINPUT }
+          ]
+        },
+        caret: { start: 1, length: 0 }
+      });
+
+      // Wait for the search suggestions to become visible.
+      let table =
+        gBrowser.contentDocument.getElementById("searchSuggestionTable");
+      let deferred = Promise.defer();
+      let observer = new MutationObserver(() => {
+        if (input.getAttribute("aria-expanded") == "true") {
+          observer.disconnect();
+          ok(!table.hidden, "Search suggestion table unhidden");
+          deferred.resolve();
+        }
+      });
+      observer.observe(input, {
+        attributes: true,
+        attributeFilter: ["aria-expanded"],
+      });
+      yield deferred.promise;
+
+      // Click the second suggestion.
+      let expectedURL = Services.search.currentEngine.
+                        getSubmission("xbar", null, "homepage").
+                        uri.spec;
+      let loadPromise = waitForDocLoadAndStopIt(expectedURL);
+      let row = table.children[1];
+      EventUtils.sendMouseEvent({ type: "mousedown" }, row, gBrowser.contentWindow);
+      yield loadPromise;
+      ok(input.value == "xbar", "Suggestion is selected");
+    });
+  }
+},
 {
   desc: "Cmd+k should focus the search box in the page when the search box in the toolbar is absent",
   setup: function () {