From e76586ede420a2bdb12bc868698572a10217b4b4 Mon Sep 17 00:00:00 2001
From: Solomon <git@solomonvictorino.com>
Date: Wed, 26 Mar 2025 23:41:16 +0000
Subject: [PATCH] reset argument/redirection state after `eval_call` errors
 (#15400)

Closes #15395

# User-Facing Changes

Certain errors no longer leave the argument stack in an unexpected
state:

```diff
 let x: any = 1; try { $x | get path } catch { print caught }
-$.path # extra `print` argument from the failed `get` call
 caught
```

# Description

If `eval_call` fails in `check_input_types` or `gather_arguments`, the
cleanup code is still executed.
---
 crates/nu-command/tests/commands/try_.rs |   8 ++
 crates/nu-engine/src/eval_ir.rs          | 100 ++++++++++++-----------
 2 files changed, 59 insertions(+), 49 deletions(-)

diff --git a/crates/nu-command/tests/commands/try_.rs b/crates/nu-command/tests/commands/try_.rs
index 7e6952d2b9..65a36db6e1 100644
--- a/crates/nu-command/tests/commands/try_.rs
+++ b/crates/nu-command/tests/commands/try_.rs
@@ -82,6 +82,14 @@ fn catch_block_can_use_error_object() {
     assert_eq!(output.out, "Division by zero.")
 }
 
+#[test]
+fn catch_input_type_mismatch_and_rethrow() {
+    let actual = nu!(
+        "let x: any = 1; try { $x | get 1 } catch {|err| error make { msg: ($err | get msg) } }"
+    );
+    assert!(actual.err.contains("Input type not supported"));
+}
+
 // This test is disabled on Windows because they cause a stack overflow in CI (but not locally!).
 // For reasons we don't understand, the Windows CI runners are prone to stack overflow.
 // TODO: investigate so we can enable on Windows
diff --git a/crates/nu-engine/src/eval_ir.rs b/crates/nu-engine/src/eval_ir.rs
index 20a0bda94d..6dfa913931 100644
--- a/crates/nu-engine/src/eval_ir.rs
+++ b/crates/nu-engine/src/eval_ir.rs
@@ -1026,63 +1026,65 @@ fn eval_call<D: DebugContext>(
     // Set up redirect modes
     let mut caller_stack = caller_stack.push_redirection(redirect_out.take(), redirect_err.take());
 
-    let result;
+    let result = (|| {
+        if let Some(block_id) = decl.block_id() {
+            // If the decl is a custom command
+            let block = engine_state.get_block(block_id);
 
-    if let Some(block_id) = decl.block_id() {
-        // If the decl is a custom command
-        let block = engine_state.get_block(block_id);
+            // check types after acquiring block to avoid unnecessarily cloning Signature
+            check_input_types(&input, &block.signature, head)?;
 
-        // check types after acquiring block to avoid unnecessarily cloning Signature
-        check_input_types(&input, &block.signature, head)?;
+            // Set up a callee stack with the captures and move arguments from the stack into variables
+            let mut callee_stack = caller_stack.gather_captures(engine_state, &block.captures);
 
-        // Set up a callee stack with the captures and move arguments from the stack into variables
-        let mut callee_stack = caller_stack.gather_captures(engine_state, &block.captures);
+            gather_arguments(
+                engine_state,
+                block,
+                &mut caller_stack,
+                &mut callee_stack,
+                *args_base,
+                args_len,
+                head,
+            )?;
 
-        gather_arguments(
-            engine_state,
-            block,
-            &mut caller_stack,
-            &mut callee_stack,
-            *args_base,
-            args_len,
-            head,
-        )?;
+            // Add one to the recursion count, so we don't recurse too deep. Stack overflows are not
+            // recoverable in Rust.
+            callee_stack.recursion_count += 1;
 
-        // Add one to the recursion count, so we don't recurse too deep. Stack overflows are not
-        // recoverable in Rust.
-        callee_stack.recursion_count += 1;
+            let result =
+                eval_block_with_early_return::<D>(engine_state, &mut callee_stack, block, input);
 
-        result = eval_block_with_early_return::<D>(engine_state, &mut callee_stack, block, input);
+            // Move environment variables back into the caller stack scope if requested to do so
+            if block.redirect_env {
+                redirect_env(engine_state, &mut caller_stack, &callee_stack);
+            }
 
-        // Move environment variables back into the caller stack scope if requested to do so
-        if block.redirect_env {
-            redirect_env(engine_state, &mut caller_stack, &callee_stack);
+            result
+        } else {
+            check_input_types(&input, &decl.signature(), head)?;
+            // FIXME: precalculate this and save it somewhere
+            let span = Span::merge_many(
+                std::iter::once(head).chain(
+                    caller_stack
+                        .arguments
+                        .get_args(*args_base, args_len)
+                        .iter()
+                        .flat_map(|arg| arg.span()),
+                ),
+            );
+
+            let call = Call {
+                decl_id,
+                head,
+                span,
+                args_base: *args_base,
+                args_len,
+            };
+
+            // Run the call
+            decl.run(engine_state, &mut caller_stack, &(&call).into(), input)
         }
-    } else {
-        check_input_types(&input, &decl.signature(), head)?;
-
-        // FIXME: precalculate this and save it somewhere
-        let span = Span::merge_many(
-            std::iter::once(head).chain(
-                caller_stack
-                    .arguments
-                    .get_args(*args_base, args_len)
-                    .iter()
-                    .flat_map(|arg| arg.span()),
-            ),
-        );
-
-        let call = Call {
-            decl_id,
-            head,
-            span,
-            args_base: *args_base,
-            args_len,
-        };
-
-        // Run the call
-        result = decl.run(engine_state, &mut caller_stack, &(&call).into(), input);
-    };
+    })();
 
     drop(caller_stack);