Fail safely on Windows console mode errors

src/bin/dosh-client.rs

@@ -10565,9 +10565,17 @@ impl RawMode {
     fn enter() -> Result<Self> {
         flush_local_terminal_input();
         enable_raw_mode()?;
+        #[cfg(windows)]
+        let console_modes = match WindowsConsoleModeGuard::enter() {
+            Ok(guard) => guard,
+            Err(err) => {
+                let _ = disable_raw_mode();
+                return Err(err);
+            }
+        };
         let raw = Self {
             #[cfg(windows)]
-            console_modes: WindowsConsoleModeGuard::enter(),
+            console_modes,
         };
         flush_local_terminal_input();
         drain_local_terminal_input();
@@ -10614,7 +10622,7 @@ struct WindowsConsoleModeGuard {
 
 #[cfg(windows)]
 impl WindowsConsoleModeGuard {
-    fn enter() -> Self {
+    fn enter() -> Result<Self> {
         unsafe {
             use windows_sys::Win32::Foundation::INVALID_HANDLE_VALUE;
             use windows_sys::Win32::System::Console::{
@@ -10630,8 +10638,9 @@ impl WindowsConsoleModeGuard {
                     None
                 } else {
                     let desired = windows_vt_input_mode(original);
-                    if desired != original {
+                    if desired != original && SetConsoleMode(input_handle, desired) == 0 {
-                        let _ = SetConsoleMode(input_handle, desired);
+                        return Err(std::io::Error::last_os_error())
+                            .context("enable Windows virtual-terminal input mode");
                     }
                     Some((input_handle, original))
                 }
@@ -10646,14 +10655,18 @@ impl WindowsConsoleModeGuard {
                     None
                 } else {
                     let desired = windows_vt_output_mode(original);
-                    if desired != original {
+                    if desired != original && SetConsoleMode(output_handle, desired) == 0 {
-                        let _ = SetConsoleMode(output_handle, desired);
+                        let err = std::io::Error::last_os_error();
+                        if let Some((handle, mode)) = input {
+                            let _ = SetConsoleMode(handle, mode);
+                        }
+                        return Err(err).context("enable Windows virtual-terminal output mode");
                     }
                     Some((output_handle, original))
                 }
             };
 
-            Self { input, output }
+            Ok(Self { input, output })
         }
     }