Add new inherit_handles flag to CommandExt trait

This patch adds a new flag to the [`CommandExt`](1) trait to set whether to
inherit the handles of the calling process (2) on Windows systems.

ACP: rust-lang/libs-team#264

[1]: https://doc.rust-lang.org/stable/std/os/windows/process/trait.CommandExt.html
[2]: https://learn.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-createprocessw

Author: michaelvanstraten

std/src/os/windows/process.rs

@@ -365,6 +365,20 @@ pub trait CommandExt: Sealed {
     /// [1]: https://learn.microsoft.com/en-us/windows/win32/api/processthreadsapi/ns-processthreadsapi-startupinfoa
     #[unstable(feature = "windows_process_extensions_startupinfo", issue = "141010")]
     fn startupinfo_force_feedback(&mut self, enabled: Option<bool>) -> &mut process::Command;
+
+    /// If this flag is set to `true`, each inheritable handle in the calling
+    /// process is inherited by the new process. If the flag is `false`, the
+    /// handles are not inherited.
+    ///
+    /// The default value for this flag is `true`.
+    ///
+    /// **Note** that inherited handles have the same value and access rights
+    /// as the original handles. For additional discussion of inheritable handles,
+    /// see the [Remarks][1] section of the `CreateProcessW` documentation.
+    ///
+    /// [1]: https://learn.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-createprocessw#remarks
+    #[unstable(feature = "windows_process_extensions_inherit_handles", issue = "146407")]
+    fn inherit_handles(&mut self, inherit_handles: bool) -> &mut process::Command;
 }
 
 #[stable(feature = "windows_process_extensions", since = "1.16.0")]
@@ -421,6 +435,11 @@ impl CommandExt for process::Command {
         self.as_inner_mut().startupinfo_force_feedback(enabled);
         self
     }
+
+    fn inherit_handles(&mut self, inherit_handles: bool) -> &mut process::Command {
+        self.as_inner_mut().inherit_handles(inherit_handles);
+        self
+    }
 }
 
 #[unstable(feature = "windows_process_extensions_main_thread_handle", issue = "96723")]

std/src/sys/process/windows.rs

@@ -159,6 +159,7 @@ pub struct Command {
     startupinfo_fullscreen: bool,
     startupinfo_untrusted_source: bool,
     startupinfo_force_feedback: Option<bool>,
+    inherit_handles: bool,
 }
 
 pub enum Stdio {
@@ -187,6 +188,7 @@ impl Command {
             startupinfo_fullscreen: false,
             startupinfo_untrusted_source: false,
             startupinfo_force_feedback: None,
+            inherit_handles: true,
         }
     }
 
@@ -252,6 +254,10 @@ impl Command {
         self.cwd.as_ref().map(Path::new)
     }
 
+    pub fn inherit_handles(&mut self, inherit_handles: bool) {
+        self.inherit_handles = inherit_handles;
+    }
+
     pub fn spawn(
         &mut self,
         default: Stdio,
@@ -310,6 +316,7 @@ impl Command {
             flags |= c::DETACHED_PROCESS | c::CREATE_NEW_PROCESS_GROUP;
         }
 
+        let inherit_handles = self.inherit_handles as c::BOOL;
         let (envp, _data) = make_envp(maybe_env)?;
         let (dirp, _data) = make_dirp(self.cwd.as_ref())?;
         let mut pi = zeroed_process_information();
@@ -401,7 +408,7 @@ impl Command {
                 cmd_str.as_mut_ptr(),
                 ptr::null_mut(),
                 ptr::null_mut(),
-                c::TRUE,
+                inherit_handles,
                 flags,
                 envp,
                 dirp,