fix: automatically skip stdio initialization when NUL is unavailable (#53459)

Automatically set kNoStdioInitialization on Windows when the NUL device
cannot be opened, rather than aborting startup. Apply this to both
embedded Node.js and ELECTRON_RUN_AS_NODE initialization.

Remove the --no-stdio-init switch and its child-process forwarding, and
update the command-line and breaking changes documentation. Preserve
normal stdio initialization when NUL is available and on other platforms.

Closes #52677

Assisted-By: GPT 6.1 Sol

docs/api/command-line-switches.md

@@ -197,11 +197,6 @@ Disables the Chromium [sandbox](https://www.chromium.org/developers/design-docum
 Forces renderer process and Chromium helper processes to run un-sandboxed.
 Should only be used for testing.
 
-### --no-stdio-init
-
-Disable stdio initialization during node initialization.
-Used to avoid node initialization crash when the nul device is disabled on Windows platform.
-
 ### --ozone-platform=`platform` _Linux_
 
 Forces Electron to use a specific display backend instead of choosing one

docs/breaking-changes.md

@@ -16,6 +16,18 @@ This document uses the following convention to categorize breaking changes:
 
 ## Breaking API Changes (46.0)
 
+### Removed: `--no-stdio-init` command-line switch
+
+The `--no-stdio-init` command-line switch has been removed.
+
+On Windows, Electron now automatically skips Node.js stdio initialization when
+the `NUL` device cannot be opened, instead of aborting startup. This applies to
+both regular Electron processes and `ELECTRON_RUN_AS_NODE` mode. Stdio
+initialization remains enabled when `NUL` is available.
+
+Remove this switch from application launch arguments. No replacement is needed
+for the Windows `NUL` device workaround.
+
 ### Behavior Changed: `utilityProcess` `child.kill()` no longer force-kills the child
 
 `child.kill()` used to send `SIGTERM` and then `SIGKILL` two seconds later if the

shell/app/node_main.cc

@@ -33,7 +33,6 @@
 #include "shell/common/node_bindings.h"
 #include "shell/common/node_includes.h"
 #include "shell/common/node_util.h"
-#include "shell/common/options_switches.h"
 #include "shell/common/platform_util.h"
 #include "third_party/electron_node/src/tracing/agent.h"
 
@@ -161,9 +160,8 @@ int NodeMain() {
   v8_crashpad_support::SetUp();
 #endif
 
-  auto* command_line = base::CommandLine::ForCurrentProcess();
-
 #if BUILDFLAG(IS_LINUX)
+  auto* command_line = base::CommandLine::ForCurrentProcess();
   int pid = -1;
   std::optional<std::string> fd_string = os_env->GetVar("CRASHDUMP_SIGNAL_FD");
   std::optional<std::string> pid_string =
@@ -211,20 +209,11 @@ int NodeMain() {
         node::ProcessInitializationFlags::kNoInitializeV8 |
         node::ProcessInitializationFlags::kNoInitializeNodeV8Platform;
 
-    if (command_line->HasSwitch(switches::kNoStdioInit)) {
-      process_flags |= node::ProcessInitializationFlags::kNoStdioInitialization;
-      // remove the option to avoid node error "bad option: --no-stdio-init"
-      std::string option = std::string("--") + switches::kNoStdioInit;
-      std::erase(args, option);
-    } else {
 #if BUILDFLAG(IS_WIN)
-      if (!platform_util::IsNulDeviceEnabled()) {
-        LOG(FATAL) << "Unable to open nul device needed for initialization,"
-                      "aborting startup. As a workaround, try starting with --"
-                   << switches::kNoStdioInit;
-      }
+    // Node.js aborts when it cannot replace missing stdio handles with NUL.
+    if (!platform_util::IsNulDeviceEnabled())
+      process_flags |= node::ProcessInitializationFlags::kNoStdioInitialization;
 #endif
-    }
 
     std::shared_ptr<node::InitializationResult> result =
         node::InitializeOncePerProcess(

shell/browser/electron_browser_client.cc

@@ -644,7 +644,7 @@ void ElectronBrowserClient::AppendExtraCommandLineSwitches(
   if (process_type == ::switches::kUtilityProcess ||
       process_type == ::switches::kRendererProcess) {
     // Copy following switches to child process.
-    static constexpr std::array<const char*, 11U> kCommonSwitchNames = {
+    static constexpr std::array<const char*, 10U> kCommonSwitchNames = {
         switches::kStandardSchemes.c_str(),
         switches::kEnableSandbox.c_str(),
         switches::kSecureSchemes.c_str(),
@@ -653,7 +653,6 @@ void ElectronBrowserClient::AppendExtraCommandLineSwitches(
         switches::kFetchSchemes.c_str(),
         switches::kServiceWorkerSchemes.c_str(),
         switches::kStreamingSchemes.c_str(),
-        switches::kNoStdioInit.c_str(),
         switches::kCodeCacheSchemes.c_str(),
         switches::kExtensionSchemes.c_str()};
     command_line->CopySwitchesFrom(*base::CommandLine::ForCurrentProcess(),

shell/common/node_bindings.cc

@@ -45,7 +45,6 @@
 #include "shell/common/mac/main_application_bundle.h"
 #include "shell/common/node_includes.h"
 #include "shell/common/node_util.h"
-#include "shell/common/options_switches.h"
 #include "shell/common/platform_util.h"
 #include "shell/common/process_util.h"
 #include "shell/common/world_ids.h"
@@ -733,18 +732,11 @@ void NodeBindings::Initialize(v8::Isolate* const isolate,
   if (!fuses::IsNodeOptionsEnabled())
     process_flags |= node::ProcessInitializationFlags::kDisableNodeOptionsEnv;
 
-  base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
-  if (command_line->HasSwitch(switches::kNoStdioInit)) {
-    process_flags |= node::ProcessInitializationFlags::kNoStdioInitialization;
-  } else {
 #if BUILDFLAG(IS_WIN)
-    if (!platform_util::IsNulDeviceEnabled()) {
-      LOG(FATAL) << "Unable to open nul device needed for initialization,"
-                    "aborting startup. As a workaround, try starting with --"
-                 << switches::kNoStdioInit;
-    }
+  // Node.js aborts when it cannot replace missing stdio handles with NUL.
+  if (!platform_util::IsNulDeviceEnabled())
+    process_flags |= node::ProcessInitializationFlags::kNoStdioInitialization;
 #endif
-  }
 
   std::shared_ptr<node::InitializationResult> result =
       node::InitializeOncePerProcess(

shell/common/options_switches.h

@@ -331,10 +331,6 @@ inline constexpr base::cstring_view kEnableAuthNegotiatePort =
 // If set, NTLM v2 is disabled for POSIX platforms.
 inline constexpr base::cstring_view kDisableNTLMv2 = "disable-ntlm-v2";
 
-// If set, flag node::ProcessInitializationFlags::kNoStdioInitialization would
-// be set for node initialization.
-inline constexpr base::cstring_view kNoStdioInit = "no-stdio-init";
-
 }  // namespace switches
 
 }  // namespace electron