fix: a reused destination retires the routes pointing at it, and draft_base stays out of diffs

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

backend/.sqlx/query-9723edfd6de38cf0bf21123a46d88fa7d0b650b5cfd80c099f785f5e411062e5.json

@@ -1,16 +1,17 @@
 {
   "db_name": "PostgreSQL",
-  "query": "DELETE FROM draft_move WHERE workspace_id = $1 AND typ::text = ANY($2::text[]) AND old_path = $3",
+  "query": "DELETE FROM draft_move WHERE workspace_id = $1 AND typ::text = ANY($2::text[])\n           AND (old_path = $3 OR (new_path = $3 AND $4::text IS NULL))",
   "describe": {
     "columns": [],
     "parameters": {
       "Left": [
         "Text",
         "TextArray",
+        "Text",
         "Text"
       ]
     },
     "nullable": []
   },
-  "hash": "b6af374e5043a207eae6bce80d3eccda82aec0ae80ccdf2445570e369e0d815a"
+  "hash": "9723edfd6de38cf0bf21123a46d88fa7d0b650b5cfd80c099f785f5e411062e5"
 }

backend/.sqlx/query-9d1b202844e6935e636d1570a92d46af4419dda9410ffc46f19bc38e56efe609.json

@@ -0,0 +1,18 @@
+{
+  "db_name": "PostgreSQL",
+  "query": "DELETE FROM draft_move\n         WHERE workspace_id = $1 AND typ::text = ANY($2::text[])\n           AND new_path = $4 AND old_path <> $3 AND ($5::text IS NULL OR email = $5)",
+  "describe": {
+    "columns": [],
+    "parameters": {
+      "Left": [
+        "Text",
+        "TextArray",
+        "Text",
+        "Text",
+        "Text"
+      ]
+    },
+    "nullable": []
+  },
+  "hash": "9d1b202844e6935e636d1570a92d46af4419dda9410ffc46f19bc38e56efe609"
+}

backend/tests/drafts_save_follows_move.rs

@@ -530,3 +530,58 @@ async fn test_a_moved_draft_deploys_at_its_new_path(db: Pool<Postgres>) -> anyho
     assert_eq!(status, 201, "the moved draft could not be deployed: {body}");
     Ok(())
 }
+
+/// A route is only as good as the item it points at: when an unrelated item claims the
+/// destination, a save still addressed to the old path must stay where it is rather than
+/// land on that item's draft.
+#[sqlx::test(fixtures("base", "drafts_save_follows_move"))]
+async fn test_a_reused_destination_ends_the_route(db: Pool<Postgres>) -> anyhow::Result<()> {
+    initialize_tracing().await;
+    let server = ApiServer::start(db.clone()).await?;
+    let port = server.addr.port();
+
+    sqlx::query("UPDATE script SET archived = true WHERE path = 'u/test-user/follow_a'")
+        .execute(&db)
+        .await?;
+    let resp = reqwest::Client::new()
+        .post(format!(
+            "http://localhost:{port}/api/w/test-workspace/drafts/move/script/u/test-user/follow_a"
+        ))
+        .header("Authorization", "Bearer SECRET_TOKEN")
+        .json(&json!({ "new_path": "u/test-user/follow_b" }))
+        .send()
+        .await?;
+    assert!(
+        resp.status().is_success(),
+        "move failed: {}",
+        resp.text().await?
+    );
+    // Someone else's item takes the destination, and the moved draft goes with the
+    // deploy that consumes it.
+    sqlx::query("DELETE FROM draft WHERE workspace_id = 'test-workspace' AND path = 'u/test-user/follow_b'")
+        .execute(&db)
+        .await?;
+    let resp = reqwest::Client::new()
+        .post(format!(
+            "http://localhost:{port}/api/w/test-workspace/scripts/create"
+        ))
+        .header("Authorization", "Bearer SECRET_TOKEN")
+        .json(&json!({
+            "path": "u/test-user/follow_b",
+            "summary": "unrelated",
+            "description": "",
+            "content": "export function main() { return 3 }",
+            "language": "deno",
+            "schema": {}
+        }))
+        .send()
+        .await?;
+    assert_eq!(resp.status(), 201, "create failed: {}", resp.text().await?);
+
+    assert_eq!(
+        save_at(port, "u/test-user/follow_a", "after the destination was reused").await?,
+        "u/test-user/follow_a",
+        "a save was routed onto the item that now owns the destination"
+    );
+    Ok(())
+}

backend/windmill-api-flows/src/flows.rs

@@ -719,6 +719,7 @@ async fn create_flow(
         &w_id,
         &[UserDraftItemKind::Flow],
         &nf.path,
+        None,
     )
     .await?;
 

backend/windmill-api-scripts/src/scripts.rs

@@ -2426,6 +2426,7 @@ async fn create_script_internal<'c>(
         &w_id,
         &[UserDraftItemKind::Script],
         &ns.path,
+        p_path_opt.as_deref(),
     )
     .await?;
     if p_hashes.is_some() && !p_hashes.unwrap().is_empty() {

backend/windmill-api/src/apps.rs

@@ -2611,6 +2611,7 @@ async fn create_app_internal<'a>(
         &w_id,
         &[UserDraftItemKind::App, UserDraftItemKind::RawApp],
         &app.path,
+        None,
     )
     .await?;
     let id = sqlx::query_scalar!(

backend/windmill-common/src/user_drafts.rs

@@ -790,6 +790,21 @@ pub async fn record_draft_move(
     )
     .execute(&mut **tx)
     .await?;
+    // Routes that ended at the destination before this move describe drafts that were
+    // carried there for an item this one is replacing: left alive, a save addressed to
+    // the start of that chain would land on this move's draft instead.
+    sqlx::query!(
+        "DELETE FROM draft_move
+         WHERE workspace_id = $1 AND typ::text = ANY($2::text[])
+           AND new_path = $4 AND old_path <> $3 AND ($5::text IS NULL OR email = $5)",
+        w_id,
+        &typs as &[&str],
+        old_path,
+        new_path,
+        email,
+    )
+    .execute(&mut **tx)
+    .await?;
     sqlx::query!(
         "UPDATE draft_move SET new_path = $4
          WHERE workspace_id = $1 AND typ::text = ANY($2::text[])
@@ -842,8 +857,11 @@ pub async fn record_draft_move(
     Ok(())
 }
 
-/// Drop the move records leaving `path`: an item was just created there, and saves
-/// addressed to it are its own.
+/// Drop the move records at `path`: an item was just created there, so saves addressed to
+/// it are its own (records leaving `path`). A deploy that is not a rename also drops the
+/// records arriving, which point at an item that no longer owns the path; `keep_from`,
+/// the path a rename came from, suppresses that, since the chain ending here is the one
+/// this very deploy just wrote.
 ///
 /// **The caller must have authorized the deploy that created the item first.**
 /// Dropping a record sends later draft writes at `path` back to `path`.
@@ -852,13 +870,16 @@ pub async fn clear_draft_moves_from(
     w_id: &str,
     kinds: &[UserDraftItemKind],
     path: &str,
+    keep_from: Option<&str>,
 ) -> Result<()> {
     let typs = kinds.iter().map(|k| k.as_str()).collect::<Vec<_>>();
     sqlx::query!(
-        "DELETE FROM draft_move WHERE workspace_id = $1 AND typ::text = ANY($2::text[]) AND old_path = $3",
+        "DELETE FROM draft_move WHERE workspace_id = $1 AND typ::text = ANY($2::text[])
+           AND (old_path = $3 OR (new_path = $3 AND $4::text IS NULL))",
         w_id,
         &typs as &[&str],
         path,
+        keep_from,
     )
     .execute(&mut **tx)
     .await?;

frontend/src/lib/utils.ts

@@ -1442,6 +1442,7 @@ const CLEANED_VALUE_KEYS = new Set([
 	'draft_only',
 	'draft_saved_at',
 	'draft_created_at',
+	'draft_base',
 	'is_draft',
 	'other_drafts_users',
 	'created_at',

frontend/src/lib/utils_draft_deploy.ts

@@ -262,7 +262,7 @@ export async function getDraftDiffValues(
 	// draft-table row (e.g. a flow created via createFlow(draft_only: true), like
 	// `u/admin/new`). There `draft` is null, so the draft side must fall back to
 	// the row's own value — otherwise the diff "after" is empty and nothing shows.
-	// Strip overlay metadata (is_draft / draft_saved_at / no_deployed /
+	// Strip overlay metadata (is_draft / draft_saved_at / draft_base / no_deployed /
 	// other_drafts_users) from the deployed side so the diff doesn't show the
 	// per-user markers as noise.
 	if (kind === 'script') {
@@ -271,6 +271,7 @@ export async function getDraftDiffValues(
 			draft,
 			is_draft: _i,
 			draft_saved_at: _c,
+			draft_base: _b,
 			no_deployed,
 			other_drafts_users: _o,
 			hash: _h,
@@ -289,6 +290,7 @@ export async function getDraftDiffValues(
 			draft,
 			is_draft: _i,
 			draft_saved_at: _c,
+			draft_base: _b,
 			no_deployed,
 			other_drafts_users: _o,
 			version_id: _v,