Bug 40166: Disable security.certerrors.mitm.auto_enable_enterprise_roots

browser/app/profile/000-tor-browser.js

@@ -313,6 +313,9 @@ pref("security.enterprise_roots.enabled", false);
 // Don't ping Mozilla for MitM detection, see bug 32321
 pref("security.certerrors.mitm.priming.enabled", false);
 
+// Don't automatically enable enterprise roots, see bug 40166
+pref("security.certerrors.mitm.auto_enable_enterprise_roots", false);
+
 // Disable the language pack signing check for now on macOS, see #31942
 #ifdef XP_MACOSX
 pref("extensions.langpacks.signatures.required", false);

browser/components/BrowserGlue.jsm

@@ -1346,6 +1346,20 @@ BrowserGlue.prototype = {
     // handle any UI migration
     this._migrateUI();
 
+    // Clear possibly auto enabled enterprise_roots prefs (see bug 40166)
+    if (
+      !Services.prefs.getBoolPref(
+        "security.certerrors.mitm.auto_enable_enterprise_roots"
+      ) &&
+      Services.prefs.getBoolPref(
+        "security.enterprise_roots.auto-enabled",
+        false
+      )
+    ) {
+      Services.prefs.clearUserPref("security.enterprise_roots.enabled");
+      Services.prefs.clearUserPref("security.enterprise_roots.auto-enabled");
+    }
+
     if (!Services.prefs.prefHasUserValue(PREF_PDFJS_ISDEFAULT_CACHE_STATE)) {
       PdfJs.checkIsDefault(this._isNewProfile);
     }