From 8a6d967f071e3c06296a01bc291a63ca9870b9ea Mon Sep 17 00:00:00 2001
From: Urgau <urgau@numericable.fr>
Date: Wed, 12 Nov 2025 19:04:57 +0100
Subject: [PATCH 1/2] Move rfcbot FCP check to utils and error on `concern`
 command

---
 src/handlers/concern.rs | 24 ++++++------------------
 src/utils.rs            | 21 +++++++++++++++++++++
 2 files changed, 27 insertions(+), 18 deletions(-)

diff --git a/src/handlers/concern.rs b/src/handlers/concern.rs
index a6b509ea..9a589e12 100644
--- a/src/handlers/concern.rs
+++ b/src/handlers/concern.rs
@@ -8,6 +8,7 @@ use crate::{
     github::{Event, Label},
     handlers::Context,
     interactions::EditIssueBody,
+    utils::is_issue_under_rfcbot_fcp,
 };
 use parser::command::concern::ConcernCommand;
 
@@ -45,24 +46,11 @@ pub(super) async fn handle_command(
     };
     let issue = &issue_comment.issue;
 
-    // Verify that this issue isn't a rfcbot FCP, skip if it is
-    match crate::rfcbot::get_all_fcps().await {
-        Ok(fcps) => {
-            if fcps.iter().any(|(_, fcp)| {
-                u64::from(fcp.issue.number) == issue.number
-                    && fcp.issue.repository == issue_comment.repository.full_name
-            }) {
-                tracing::info!(
-                    "{}#{} tried to register a concern, blocked by our rfcbot FCP check",
-                    issue_comment.repository.full_name,
-                    issue.number,
-                );
-                return Ok(());
-            }
-        }
-        Err(err) => {
-            tracing::warn!("unable to fetch rfcbot active FCPs: {err:?}, skipping check");
-        }
+    // Verify that this issue isn't a rfcbot FCP
+    if is_issue_under_rfcbot_fcp(&issue_comment.repository.full_name, issue.number).await {
+        return user_error!(
+            "Cannot set `@rustbot concern` on an active [rfcbot](https://rfcbot.rs/) FCP, use `@rfcbot concern` instead."
+        );
     }
 
     // Verify that the comment author is a team member in our team repo
diff --git a/src/utils.rs b/src/utils.rs
index ab65d2ea..cd78c854 100644
--- a/src/utils.rs
+++ b/src/utils.rs
@@ -35,3 +35,24 @@ pub(crate) async fn is_repo_autorized(
 
     Ok(true)
 }
+
+pub(crate) async fn is_issue_under_rfcbot_fcp(
+    issue_full_repo_name: &str,
+    issue_number: u64,
+) -> bool {
+    match crate::rfcbot::get_all_fcps().await {
+        Ok(fcps) => {
+            if fcps.iter().any(|(_, fcp)| {
+                u64::from(fcp.issue.number) == issue_number
+                    && fcp.issue.repository == issue_full_repo_name
+            }) {
+                return true;
+            }
+        }
+        Err(err) => {
+            tracing::warn!("unable to fetch rfcbot active FCPs: {err:?}, skipping check");
+        }
+    }
+
+    false
+}

From c24d8630a2cfbe9fc19cb0d749479cff81b6b83c Mon Sep 17 00:00:00 2001
From: Urgau <urgau@numericable.fr>
Date: Wed, 12 Nov 2025 19:05:48 +0100
Subject: [PATCH 2/2] Block acceptance and second of major change under active
 rfcbot FCP

---
 src/handlers/major_change.rs | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/src/handlers/major_change.rs b/src/handlers/major_change.rs
index 661dde46..fdf51bed 100644
--- a/src/handlers/major_change.rs
+++ b/src/handlers/major_change.rs
@@ -2,6 +2,7 @@ use std::fmt::Display;
 
 use crate::errors::user_error;
 use crate::jobs::Job;
+use crate::utils::is_issue_under_rfcbot_fcp;
 use crate::zulip::api::Recipient;
 use crate::{
     config::MajorChangeConfig,
@@ -262,6 +263,13 @@ pub(super) async fn handle_command(
         return user_error!("Only team members can second issues.");
     }
 
+    // Verify that this issue isn't a rfcbot FCP
+    if is_issue_under_rfcbot_fcp(&issue.repository().full_repo_name(), issue.number).await {
+        return user_error!(
+            "Cannot second a major change on an active [rfcbot](https://rfcbot.rs/) FCP."
+        );
+    }
+
     let has_concerns = if let Some(concerns_label) = &config.concerns_label {
         issue.labels().iter().any(|l| &l.name == concerns_label)
     } else {
@@ -474,6 +482,7 @@ enum SecondedLogicError {
         at: DateTime<Utc>,
     },
     NoMajorChangeConfig,
+    UnderRfcBotFcp,
 }
 
 impl std::error::Error for SecondedLogicError {}
@@ -506,6 +515,7 @@ impl Display for SecondedLogicError {
                 write!(f, "concerns label added at {at}")
             }
             SecondedLogicError::NoMajorChangeConfig => write!(f, "no `[major_change]` config"),
+            SecondedLogicError::UnderRfcBotFcp => write!(f, "under rfcbot fcp"),
         }
     }
 }
@@ -679,6 +689,10 @@ async fn try_accept_mcp(
                 open: issue.is_open()
             });
         }
+
+        if is_issue_under_rfcbot_fcp(&major_change.repo, major_change.issue).await {
+            anyhow::bail!(SecondedLogicError::UnderRfcBotFcp);
+        }
     }
 
     if !issue.labels.iter().any(|l| l.name == config.accept_label) {