From 04531357b40a37fcbcc164ddd3c38222507c3e5a Mon Sep 17 00:00:00 2001
From: pwygab <88221256+merelymyself@users.noreply.github.com>
Date: Fri, 29 Mar 2024 04:40:45 +0800
Subject: [PATCH] Exposed the recursion limit value as a config option (#12308)

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# Description
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Thank you for improving Nushell. Please, check our [contributing
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Closes #12253.

Exposes the option as "recursion_limit" under config.

# User-Facing Changes
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helps us keep track of breaking changes. -->

The config file now has a new option!

# After Submitting
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documentation](https://github.com/nushell/nushell.github.io) after the
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Nothing else...? Do let me know if there's something I've missed!
---
 crates/nu-engine/src/eval.rs                      |  6 +++---
 crates/nu-protocol/src/config/mod.rs              | 15 +++++++++++++++
 .../nu-utils/src/sample_config/default_config.nu  |  1 +
 3 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/crates/nu-engine/src/eval.rs b/crates/nu-engine/src/eval.rs
index 0541125ed7..c56cc8d223 100644
--- a/crates/nu-engine/src/eval.rs
+++ b/crates/nu-engine/src/eval.rs
@@ -47,12 +47,12 @@ pub fn eval_call<D: DebugContext>(
         // To prevent a stack overflow in user code from crashing the shell,
         // we limit the recursion depth of function calls.
         // Picked 50 arbitrarily, should work on all architectures.
-        const MAXIMUM_CALL_STACK_DEPTH: u64 = 50;
+        let maximum_call_stack_depth: u64 = engine_state.config.recursion_limit as u64;
         callee_stack.recursion_count += 1;
-        if callee_stack.recursion_count > MAXIMUM_CALL_STACK_DEPTH {
+        if callee_stack.recursion_count > maximum_call_stack_depth {
             callee_stack.recursion_count = 0;
             return Err(ShellError::RecursionLimitReached {
-                recursion_limit: MAXIMUM_CALL_STACK_DEPTH,
+                recursion_limit: maximum_call_stack_depth,
                 span: block.span,
             });
         }
diff --git a/crates/nu-protocol/src/config/mod.rs b/crates/nu-protocol/src/config/mod.rs
index 72c1c9a7c8..59c24fac0b 100644
--- a/crates/nu-protocol/src/config/mod.rs
+++ b/crates/nu-protocol/src/config/mod.rs
@@ -61,6 +61,7 @@ pub struct Config {
     pub footer_mode: FooterMode,
     pub float_precision: i64,
     pub max_external_completion_results: i64,
+    pub recursion_limit: i64,
     pub filesize_format: String,
     pub use_ansi_coloring: bool,
     pub quick_completions: bool,
@@ -133,6 +134,7 @@ impl Default for Config {
             completion_algorithm: CompletionAlgorithm::default(),
             enable_external_completion: true,
             max_external_completion_results: 100,
+            recursion_limit: 50,
             external_completer: None,
             use_ls_colors_completions: true,
 
@@ -753,6 +755,19 @@ impl Value {
                             value,
                             &mut errors);
                     }
+                    "recursion_limit" => {
+                        if let Value::Int { val, internal_span } = value {
+                            if val > &mut 1 {
+                                config.recursion_limit = *val;
+                            } else {
+                                report_invalid_value("should be a integer greater than 1", span, &mut errors);
+                                *value = Value::Int { val: 50, internal_span: *internal_span };
+                            }
+                        } else {
+                            report_invalid_value("should be a integer greater than 1", span, &mut errors);
+                            *value = Value::Int { val: 50, internal_span: value.span() };
+                        }
+                    }
                     // Catch all
                     _ => {
                         report_invalid_key(&[key], span, &mut errors);
diff --git a/crates/nu-utils/src/sample_config/default_config.nu b/crates/nu-utils/src/sample_config/default_config.nu
index 411825e775..5286f8b53a 100644
--- a/crates/nu-utils/src/sample_config/default_config.nu
+++ b/crates/nu-utils/src/sample_config/default_config.nu
@@ -238,6 +238,7 @@ $env.config = {
     render_right_prompt_on_last_line: false # true or false to enable or disable right prompt to be rendered on last line of the prompt.
     use_kitty_protocol: false # enables keyboard enhancement protocol implemented by kitty console, only if your terminal support this.
     highlight_resolved_externals: false # true enables highlighting of external commands in the repl resolved by which.
+    recursion_limit: 50 # the maximum number of times nushell allows recursion before stopping it
 
     plugins: {} # Per-plugin configuration. See https://www.nushell.sh/contributor-book/plugins.html#configuration.