diff --git a/toolkit/mozapps/extensions/XPIProvider.jsm b/toolkit/mozapps/extensions/XPIProvider.jsm
index bbfee92bc355..7a3e830dbb78 100644
--- a/toolkit/mozapps/extensions/XPIProvider.jsm
+++ b/toolkit/mozapps/extensions/XPIProvider.jsm
@@ -1759,7 +1759,7 @@ var XPIProvider = {
     }
 
     // Ensure any changes to the add-ons list are flushed to disk
-    XPIDatabase.writeAddonsList([]);
+    XPIDatabase.writeAddonsList();
     Services.prefs.setBoolPref(PREF_PENDING_OPERATIONS, false);
   },
 
@@ -3034,8 +3034,8 @@ var XPIProvider = {
     // Check that the add-ons list still exists
     let addonsList = FileUtils.getFile(KEY_PROFILEDIR, [FILE_XPI_ADDONS_LIST],
                                        true);
-    if (!addonsList.exists()) {
-      LOG("Add-ons list is missing, recreating");
+    if (addonsList.exists() == (state.length == 0)) {
+      LOG("Add-ons list is invalid, rebuilding");
       XPIDatabase.writeAddonsList();
     }
 
@@ -5476,49 +5476,72 @@ var XPIDatabase = {
    * Writes out the XPI add-ons list for the platform to read.
    */
   writeAddonsList: function XPIDB_writeAddonsList() {
-    LOG("Writing add-ons list");
     Services.appinfo.invalidateCachesOnRestart();
+
     let addonsList = FileUtils.getFile(KEY_PROFILEDIR, [FILE_XPI_ADDONS_LIST],
                                        true);
+    if (!this.connection) {
+      try {
+        addonsList.remove(false);
+        LOG("Deleted add-ons list");
+      }
+      catch (e) {
+      }
+
+      Services.prefs.clearUserPref(PREF_EM_ENABLED_ADDONS);
+      return;
+    }
 
     let enabledAddons = [];
     let text = "[ExtensionDirs]\r\n";
     let count = 0;
-    let stmt;
+    let fullCount = 0;
 
-    if (this.connection) {
-      stmt = this.getStatement("getActiveAddons");
+    let stmt = this.getStatement("getActiveAddons");
 
-      for (let row in resultRows(stmt)) {
-        text += "Extension" + (count++) + "=" + row.descriptor + "\r\n";
-        enabledAddons.push(row.id + ":" + row.version);
-      }
+    for (let row in resultRows(stmt)) {
+      text += "Extension" + (count++) + "=" + row.descriptor + "\r\n";
+      enabledAddons.push(row.id + ":" + row.version);
     }
+    fullCount += count;
 
     // The selected skin may come from an inactive theme (the default theme
     // when a lightweight theme is applied for example)
     text += "\r\n[ThemeDirs]\r\n";
 
-    if (this.connection) {
-      if (Prefs.getBoolPref(PREF_EM_DSS_ENABLED)) {
-        stmt = this.getStatement("getThemes");
-      }
-      else {
-        stmt = this.getStatement("getActiveTheme");
-        stmt.params.internalName = XPIProvider.selectedSkin;
-      }
+    if (Prefs.getBoolPref(PREF_EM_DSS_ENABLED)) {
+      stmt = this.getStatement("getThemes");
+    }
+    else {
+      stmt = this.getStatement("getActiveTheme");
+      stmt.params.internalName = XPIProvider.selectedSkin;
+    }
+
+    if (stmt) {
       count = 0;
       for (let row in resultRows(stmt)) {
         text += "Extension" + (count++) + "=" + row.descriptor + "\r\n";
         enabledAddons.push(row.id + ":" + row.version);
       }
+      fullCount += count;
     }
 
-    var fos = FileUtils.openSafeFileOutputStream(addonsList);
-    fos.write(text, text.length);
-    FileUtils.closeSafeFileOutputStream(fos);
+    if (fullCount > 0) {
+      LOG("Writing add-ons list");
+      var fos = FileUtils.openSafeFileOutputStream(addonsList);
+      fos.write(text, text.length);
+      FileUtils.closeSafeFileOutputStream(fos);
 
-    Services.prefs.setCharPref(PREF_EM_ENABLED_ADDONS, enabledAddons.join(","));
+      Services.prefs.setCharPref(PREF_EM_ENABLED_ADDONS, enabledAddons.join(","));
+    }
+    else {
+      if (addonsList.exists()) {
+        LOG("Deleting add-ons list");
+        addonsList.remove(false);
+      }
+
+      Services.prefs.clearUserPref(PREF_EM_ENABLED_ADDONS);
+    }
   }
 };
 
diff --git a/toolkit/mozapps/extensions/test/xpcshell/test_bootstrap.js b/toolkit/mozapps/extensions/test/xpcshell/test_bootstrap.js
index 6adc0520a0f5..8e7c7bc92144 100644
--- a/toolkit/mozapps/extensions/test/xpcshell/test_bootstrap.js
+++ b/toolkit/mozapps/extensions/test/xpcshell/test_bootstrap.js
@@ -129,6 +129,9 @@ function run_test() {
   file.append("extensions.sqlite");
   do_check_false(file.exists());
 
+  file.leafName = "extensions.ini";
+  do_check_false(file.exists());
+
   run_test_1();
 }
 
@@ -175,6 +178,9 @@ function check_test_1() {
   file.append("extensions.sqlite");
   do_check_true(file.exists());
 
+  file.leafName = "extensions.ini";
+  do_check_false(file.exists());
+
   AddonManager.getAllInstalls(function(installs) {
     // There should be no active installs now since the install completed and
     // doesn't require a restart.
@@ -255,6 +261,10 @@ function run_test_3() {
   do_check_eq(getShutdownReason(), ADDON_DISABLE);
   do_check_not_in_crash_annotation("bootstrap1@tests.mozilla.org", "1.0");
 
+  let file = gProfD.clone();
+  file.append("extensions.ini");
+  do_check_false(file.exists());
+
   AddonManager.getAddonByID("bootstrap1@tests.mozilla.org", function(b1) {
     do_check_neq(b1, null);
     do_check_eq(b1.version, "1.0");
diff --git a/toolkit/mozapps/extensions/test/xpcshell/test_startup.js b/toolkit/mozapps/extensions/test/xpcshell/test_startup.js
index 3e4f112a1826..f4412a6bbcb9 100644
--- a/toolkit/mozapps/extensions/test/xpcshell/test_startup.js
+++ b/toolkit/mozapps/extensions/test/xpcshell/test_startup.js
@@ -136,6 +136,9 @@ function run_test() {
   file.append("extensions.sqlite");
   do_check_false(file.exists());
 
+  file.leafName = "extensions.ini";
+  do_check_false(file.exists());
+
   AddonManager.getAddonsByIDs(["addon1@tests.mozilla.org",
                                "addon2@tests.mozilla.org",
                                "addon3@tests.mozilla.org",
@@ -191,6 +194,9 @@ function run_test_1() {
   file.append("extensions.sqlite");
   do_check_true(file.exists());
 
+  file.leafName = "extensions.ini";
+  do_check_true(file.exists());
+
   AddonManager.getAddonsByIDs(["addon1@tests.mozilla.org",
                                "addon2@tests.mozilla.org",
                                "addon3@tests.mozilla.org",
@@ -292,6 +298,10 @@ function run_test_2() {
   check_startup_changes(AddonManager.STARTUP_CHANGE_ENABLED, []);
   do_check_true(gCachePurged);
 
+  var file = gProfD.clone();
+  file.append("extensions.ini");
+  do_check_true(file.exists());
+
   AddonManager.getAddonsByIDs(["addon1@tests.mozilla.org",
                                "addon2@tests.mozilla.org",
                                "addon3@tests.mozilla.org",