Bug 745154 - Disable automatic safe mode after startup crashes in debug builds or using an environment variable (r=ehsan)

toolkit/components/startup/nsAppStartup.cpp

@@ -89,6 +89,7 @@ static NS_DEFINE_CID(kAppShellCID, NS_APPSHELL_CID);
 #define kPrefLastSuccess "toolkit.startup.last_success"
 #define kPrefMaxResumedCrashes "toolkit.startup.max_resumed_crashes"
 #define kPrefRecentCrashes "toolkit.startup.recent_crashes"
+#define kPrefAlwaysUseSafeMode "toolkit.startup.always_use_safe_mode"
 
 #if defined(XP_WIN)
 #include "mozilla/perfprobe.h"
@@ -831,6 +832,17 @@ nsAppStartup::GetAutomaticSafeModeNecessary(bool *_retval)
 {
   NS_ENSURE_ARG_POINTER(_retval);
 
+  bool alwaysSafe = false;
+  Preferences::GetBool(kPrefAlwaysUseSafeMode, &alwaysSafe);
+
+  if (!alwaysSafe) {
+#if DEBUG
+    mIsSafeModeNecessary = false;
+#else
+    mIsSafeModeNecessary &= !PR_GetEnv("MOZ_DISABLE_AUTO_SAFE_MODE");
+#endif
+  }
+
   *_retval = mIsSafeModeNecessary;
   return NS_OK;
 }

toolkit/components/startup/tests/unit/test_startup_crash.js

@@ -15,8 +15,11 @@ let appStartup = Cc["@mozilla.org/toolkit/app-startup;1"].
 const pref_last_success = "toolkit.startup.last_success";
 const pref_recent_crashes = "toolkit.startup.recent_crashes";
 const pref_max_resumed_crashes = "toolkit.startup.max_resumed_crashes";
+const pref_always_use_safe_mode = "toolkit.startup.always_use_safe_mode";
 
 function run_test() {
+  prefService.setBoolPref(pref_always_use_safe_mode, true);
+
   resetTestEnv(0);
 
   test_trackStartupCrashBegin();
@@ -25,6 +28,8 @@ function run_test() {
   test_trackStartupCrashEnd_safeMode();
   test_maxResumed();
   resetTestEnv(0);
+
+  prefService.clearUserPref(pref_always_use_safe_mode);
 }
 
 // reset prefs to default