fix enable_ansi_support() for redirected STDOUT

.# Discussion

Even though it is used in sample methods included in the Microsoft documentation,
the `GetStdHandle(winapi::um::winbase::STD_OUTPUT_HANDLE)` method of retrieving the
console handle is a poor choice. It will fail if STDOUT is redirected, even when a
viable console is available. This can lead to incorrectly colored STDERR when STDOUT
is redirected.

Using `CreateFile2("CONOUT$", ...)` instead succeeds even when STDOUT and/or STDERR
are redirected.

[1]: https://docs.microsoft.com/en-us/windows/console/console-virtual-terminal-sequences#samples @@ https://archive.is/PHjnN#70.5%
[2]: https://docs.microsoft.com/en-us/windows/desktop/api/fileapi/nf-fileapi-createfile2#consoles @@ https://archive.is/7BWhB#71.8%

src/windows.rs

@@ -8,35 +8,48 @@
 /// Returns a `Result` with the Windows error code if unsuccessful.
 #[cfg(windows)]
 pub fn enable_ansi_support() -> Result<(), u32> {
-    use winapi::um::processenv::GetStdHandle;
-    use winapi::um::errhandlingapi::GetLastError;
+    // ref: https://docs.microsoft.com/en-us/windows/console/console-virtual-terminal-sequences#EXAMPLE_OF_ENABLING_VIRTUAL_TERMINAL_PROCESSING @@ https://archive.is/L7wRJ#76%
+
+    use std::ffi::OsStr;
+    use std::iter::once;
+    use std::os::windows::ffi::OsStrExt;
+    use std::ptr::null_mut;
     use winapi::um::consoleapi::{GetConsoleMode, SetConsoleMode};
+    use winapi::um::errhandlingapi::GetLastError;
+    use winapi::um::fileapi::CreateFile2;
     use winapi::um::handleapi::INVALID_HANDLE_VALUE;
 
-    const STD_OUT_HANDLE: u32 = -11i32 as u32;
     const ENABLE_VIRTUAL_TERMINAL_PROCESSING: u32 = 0x0004;
 
     unsafe {
-        // https://docs.microsoft.com/en-us/windows/console/getstdhandle
-        let std_out_handle = GetStdHandle(STD_OUT_HANDLE);
-        if std_out_handle == INVALID_HANDLE_VALUE
+        // ref: https://docs.microsoft.com/en-us/windows/desktop/api/fileapi/nf-fileapi-createfile2
+        // Using `CreateFile2("CONOUT$", ...)` to retrieve the console handle works correctly even if STDOUT and/or STDERR are redirected
+        let console_out_name: Vec<u16> = OsStr::new("CONOUT$").encode_wide().chain(once(0)).collect();
+        let console_handle = CreateFile2(
+            console_out_name.as_ptr(),
+            winapi::um::winnt::GENERIC_READ | winapi::um::winnt::GENERIC_WRITE,
+            winapi::um::winnt::FILE_SHARE_WRITE,
+            winapi::um::fileapi::OPEN_EXISTING,
+            null_mut(),
+        );
+        if console_handle == INVALID_HANDLE_VALUE
         {
-            return Err(GetLastError()); 
+            return Err(GetLastError());
         }
-        
-        // https://docs.microsoft.com/en-us/windows/console/getconsolemode
+
+        // ref: https://docs.microsoft.com/en-us/windows/console/getconsolemode
         let mut console_mode: u32 = 0;
-        if 0 == GetConsoleMode(std_out_handle, &mut console_mode)
+        if 0 == GetConsoleMode(console_handle, &mut console_mode)
         {
             return Err(GetLastError());
         }
 
         // VT processing not already enabled?
         if console_mode & ENABLE_VIRTUAL_TERMINAL_PROCESSING == 0 {
             // https://docs.microsoft.com/en-us/windows/console/setconsolemode
-            if 0 == SetConsoleMode(std_out_handle, console_mode | ENABLE_VIRTUAL_TERMINAL_PROCESSING)
+            if 0 == SetConsoleMode(console_handle, console_mode | ENABLE_VIRTUAL_TERMINAL_PROCESSING)
             {
-                return Err(GetLastError()); 
+                return Err(GetLastError());
             }
         }
     }