From e326d129267effec75ea25c7fc72134245e11f5e Mon Sep 17 00:00:00 2001
From: Moonchild <wolfbeast@users.noreply.github.com>
Date: Sun, 12 Mar 2017 11:39:16 +0100
Subject: [PATCH] Revert "Limit number of history entries saved by
 SessionStore"

---
 browser/app/profile/firefox.js                |  4 --
 .../components/sessionstore/SessionStore.jsm  | 52 +++++++++----------
 2 files changed, 26 insertions(+), 30 deletions(-)

diff --git a/browser/app/profile/firefox.js b/browser/app/profile/firefox.js
index f5c56dbe56..10d3688385 100644
--- a/browser/app/profile/firefox.js
+++ b/browser/app/profile/firefox.js
@@ -781,10 +781,6 @@ pref("browser.sessionstore.max_windows_undo", 3);
 // number of crashes that can occur before the about:sessionrestore page is displayed
 // (this pref has no effect if more than 6 hours have passed since the last crash)
 pref("browser.sessionstore.max_resumed_crashes", 1);
-// number of back button session history entries to save (-1 = all of them)
-pref("browser.sessionstore.max_serialize_back", 10);
-// number of forward button session history entries to save (-1 = all of them)
-pref("browser.sessionstore.max_serialize_forward", -1);
 // restore_on_demand overrides browser.sessionstore.max_concurrent_tabs
 // and restore_hidden_tabs. When true, tabs will not be restored until they are
 // focused (also applies to tabs that aren't visible). When false, the values
diff --git a/browser/components/sessionstore/SessionStore.jsm b/browser/components/sessionstore/SessionStore.jsm
index d627d3f628..f3468eab53 100644
--- a/browser/components/sessionstore/SessionStore.jsm
+++ b/browser/components/sessionstore/SessionStore.jsm
@@ -1861,44 +1861,44 @@ let SessionStoreInternal = {
     }
     catch (ex) { } // this could happen if we catch a tab during (de)initialization
 
-    if (history && history.count > 0) {
+    // XXXzeniko anchor navigation doesn't reset __SS_data, so we could reuse
+    //           data even when we shouldn't (e.g. Back, different anchor)
+    if (history && browser.__SS_data &&
+        browser.__SS_data.entries[history.index] &&
+        browser.__SS_data.entries[history.index].url == browser.currentURI.spec &&
+        history.index < this._sessionhistory_max_entries - 1 && !aFullData) {
+      tabData = browser.__SS_data;
+      tabData.index = history.index + 1;
+    }
+    else if (history && history.count > 0) {
       browser.__SS_hostSchemeData = [];
-
-      let oldest;
-      let maxSerializeBack = this._prefBranch.getIntPref("sessionstore.max_serialize_back");
-      if (maxSerializeBack >= 0) {
-        oldest = Math.max(0, history.index - maxSerializeBack);
-      } else { // History.getEntryAtIndex(0, ...) is the oldest.
-        oldest = 0;
-      }
-
-      let newest;
-      let maxSerializeFwd = this._prefBranch.getIntPref("sessionstore.max_serialize_forward");
-      if (maxSerializeFwd >= 0) {
-        newest = Math.min(history.count - 1, history.index + maxSerializeFwd);
-      } else { // History.getEntryAtIndex(history.count - 1, ...) is the newest.
-        newest = history.count - 1;
-      }
-
       try {
-        for (var j = oldest; j <= newest; j++) {
+        for (var j = 0; j < history.count; j++) {
           let entry = this._serializeHistoryEntry(history.getEntryAtIndex(j, false),
                                                   aFullData, aTab.pinned, browser.__SS_hostSchemeData);
           tabData.entries.push(entry);
         }
+        // If we make it through the for loop, then we're ok and we should clear
+        // any indicator of brokenness.
+        delete aTab.__SS_broken_history;
       }
       catch (ex) {
         // In some cases, getEntryAtIndex will throw. This seems to be due to
         // history.count being higher than it should be. By doing this in a
         // try-catch, we'll update history to where it breaks, assert for
-        // non-release builds, and still save sessionstore.js.
-        NS_ASSERT(false, "SessionStore failed gathering complete history " +
-                         "for the focused window/tab. See bug 669196.");
+        // non-release builds, and still save sessionstore.js. We'll track if
+        // we've shown the assert for this tab so we only show it once.
+        // cf. bug 669196.
+        if (!aTab.__SS_broken_history) {
+          // First Focus the window & tab we're having trouble with.
+          aTab.ownerDocument.defaultView.focus();
+          aTab.ownerDocument.defaultView.gBrowser.selectedTab = aTab;
+          NS_ASSERT(false, "SessionStore failed gathering complete history " +
+                           "for the focused window/tab. See bug 669196.");
+          aTab.__SS_broken_history = true;
+        }
       }
-
-      // Set the one-based index of the currently active tab,
-      // ensuring it isn't out of bounds if an exception was thrown above.
-      tabData.index = Math.min(history.index - oldest + 1, tabData.entries.length);
+      tabData.index = history.index + 1;
 
       // make sure not to cache privacy sensitive data which shouldn't get out
       if (!aFullData)