fix(external): close stdin properly in shutdown()

CHANGELOG.md

@@ -7,6 +7,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## Unreleased
 
+* engines/bin: fix stdin to be closed properly to avoid hangs in the `external` engine.
+
 ## [0.27.1] - 2025-02-17
 
 * runner: Add `Runner::set_var` method to allow adding runner-local variables for substitution.

sqllogictest-engines/src/external.rs

@@ -35,7 +35,7 @@ use tokio_util::codec::{Decoder, FramedRead};
 /// ```
 pub struct ExternalDriver {
     child: Child,
-    stdin: ChildStdin,
+    stdin: Option<ChildStdin>,
     stdout: FramedRead<ChildStdout, JsonDecoder<Output>>,
 }
 
@@ -76,7 +76,7 @@ impl ExternalDriver {
 
         Ok(Self {
             child,
-            stdin,
+            stdin: Some(stdin),
             stdout,
         })
     }
@@ -98,7 +98,11 @@ impl AsyncDB for ExternalDriver {
             sql: sql.to_string(),
         };
         let input = serde_json::to_string(&input)?;
-        self.stdin.write_all(input.as_bytes()).await?;
+        match &mut self.stdin {
+            Some(stdin) => stdin.write_all(input.as_bytes()).await?,
+            None => return Err(io::Error::from(io::ErrorKind::UnexpectedEof).into()),
+        };
+
         let output = match self.stdout.next().await {
             Some(Ok(output)) => output,
             Some(Err(e)) => return Err(e),
@@ -114,7 +118,7 @@ impl AsyncDB for ExternalDriver {
     }
 
     async fn shutdown(&mut self) {
-        self.stdin.shutdown().await.ok();
+        drop(self.stdin.take());
         self.child.wait().await.ok();
     }