Bug 739805 - Calling getTabState() on a not-yet-restored tab wipes out text and scroll data; r=zpao

browser/components/sessionstore/src/nsSessionStore.js

@@ -2090,9 +2090,6 @@ SessionStoreService.prototype = {
   _updateTextAndScrollData: function sss_updateTextAndScrollData(aWindow) {
     var browsers = aWindow.gBrowser.browsers;
     this._windows[aWindow.__SSi].tabs.forEach(function (tabData, i) {
-      if (browsers[i].__SS_data &&
-          browsers[i].__SS_tabStillLoading)
-        return; // ignore incompletely initialized tabs
       try {
         this._updateTextAndScrollDataForTab(aWindow, browsers[i], tabData);
       }
@@ -2114,6 +2111,10 @@ SessionStoreService.prototype = {
    */
   _updateTextAndScrollDataForTab:
     function sss_updateTextAndScrollDataForTab(aWindow, aBrowser, aTabData, aFullData) {
+    // we shouldn't update data for incompletely initialized tabs
+    if (aBrowser.__SS_data && aBrowser.__SS_tabStillLoading)
+      return;
+
     var tabIndex = (aTabData.index || aTabData.entries.length) - 1;
     // entry data needn't exist for tabs just initialized with an incomplete session state
     if (!aTabData.entries[tabIndex])

browser/components/sessionstore/test/Makefile.in

@@ -161,6 +161,7 @@ _BROWSER_TEST_FILES = \
 	browser_694378.js \
 	browser_705597.js \
 	browser_707862.js \
+	browser_739805.js \
 	$(NULL)
 
 ifneq ($(OS_ARCH),Darwin)

browser/components/sessionstore/test/browser_739805.js

@@ -0,0 +1,56 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+const TAB_STATE_NEEDS_RESTORE = 1;
+
+let tabState = {
+  entries: [{url: "data:text/html,<input%20id='foo'>", formdata: {"#foo": "bar"}}]
+};
+
+function test() {
+  waitForExplicitFinish();
+  Services.prefs.setBoolPref("browser.sessionstore.restore_on_demand", true);
+
+  registerCleanupFunction(function () {
+    if (gBrowser.tabs.length > 1)
+      gBrowser.removeTab(gBrowser.tabs[1]);
+    Services.prefs.clearUserPref("browser.sessionstore.restore_on_demand");
+  });
+
+  let tab = gBrowser.addTab("about:blank");
+  let browser = tab.linkedBrowser;
+
+  whenBrowserLoaded(browser, function () {
+    isnot(gBrowser.selectedTab, tab, "newly created tab is not selected");
+
+    ss.setTabState(tab, JSON.stringify(tabState));
+    is(browser.__SS_restoreState, TAB_STATE_NEEDS_RESTORE, "tab needs restoring");
+
+    let state = JSON.parse(ss.getTabState(tab));
+    let formdata = state.entries[0].formdata;
+    is(formdata && formdata["#foo"], "bar", "tab state's formdata is valid");
+
+    whenTabRestored(tab, function () {
+      let input = browser.contentDocument.getElementById("foo");
+      is(input.value, "bar", "formdata has been restored correctly");
+      finish();
+    });
+
+    // Restore the tab by selecting it.
+    gBrowser.selectedTab = tab;
+  });
+}
+
+function whenBrowserLoaded(aBrowser, aCallback) {
+  aBrowser.addEventListener("load", function onLoad() {
+    aBrowser.removeEventListener("load", onLoad, true);
+    executeSoon(aCallback);
+  }, true);
+}
+
+function whenTabRestored(aTab, aCallback) {
+  aTab.addEventListener("SSTabRestored", function onRestored() {
+    aTab.removeEventListener("SSTabRestored", onRestored);
+    executeSoon(aCallback);
+  });
+}