From c02e864873e5a0783947b7512a83f92e30bf1d61 Mon Sep 17 00:00:00 2001
From: NetterSilver <133535268+Silvertree2010@users.noreply.github.com>
Date: Wed, 14 Oct 2026 21:22:29 +0000
Subject: [PATCH] Replace every occurrence in edit.findReplace when replacement
 contains find

Found while testing crates/engine/src/cmd/edit.rs:975-981

Co-Authored-By: Claude Haiku 5.5 <noreply@anthropic.com>
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
---
 crates/engine/src/cmd/edit.rs | 15 +++++++++++----
 crates/engine/src/tests.rs    | 22 ++++++++++++++++++++++
 2 files changed, 33 insertions(+), 4 deletions(-)

diff --git a/crates/engine/src/cmd/edit.rs b/crates/engine/src/cmd/edit.rs
index 57ba9fb0..696f8dfe 100644
--- a/crates/engine/src/cmd/edit.rs
+++ b/crates/engine/src/cmd/edit.rs
@@ -970,13 +970,20 @@ fn find_replace(s: &mut Session, p: &Value) -> Result<Value> {
             }
             if let NodeKind::Text(t) = &mut n.kind {
                 // Replace occurrence by occurrence so styles shift correctly.
+                // The search resumes after each inserted replacement, so a replacement that
+                // contains `find` neither loops forever nor stops the other occurrences.
                 let mut guard = 0;
-                while let Some(pos) = t.characters.find(find.as_str()) {
-                    let start = t.characters.get(..pos).map(|x| x.chars().count()).unwrap_or(0);
-                    let len = find.chars().count();
+                let mut cursor = 0;
+                let len = find.chars().count();
+                let r_len = r.chars().count();
+                loop {
+                    let from = t.characters.char_indices().nth(cursor).map_or(t.characters.len(), |(b, _)| b);
+                    let Some(pos) = t.characters.get(from..).and_then(|tail| tail.find(find.as_str())) else { break };
+                    let start = cursor + t.characters.get(from..from + pos).map_or(0, |x| x.chars().count());
                     t.replace_range(start, start + len, r);
+                    cursor = start + r_len;
                     guard += 1;
-                    if guard > 10_000 || r.contains(find.as_str()) {
+                    if guard > 10_000 {
                         break;
                     }
                 }
diff --git a/crates/engine/src/tests.rs b/crates/engine/src/tests.rs
index 40da2f1d..04e97a73 100644
--- a/crates/engine/src/tests.rs
+++ b/crates/engine/src/tests.rs
@@ -161,6 +161,28 @@ fn text_create_autosize_and_edit() {
     assert_eq!(s.doc().unwrap().node(t).unwrap().kind.text().unwrap().characters, "Hello");
 }
 
+#[test]
+fn find_replace_replaces_every_occurrence_when_replacement_contains_find() {
+    for (text, find, replace, want) in [
+        ("cat and cat", "cat", "cats", "cats and cats"),
+        ("cat and cat", "cat", "category", "category and category"),
+        ("banana", "a", "aa", "baanaanaa"),
+    ] {
+        let mut s = sess();
+        let t = id(&s.execute("text.create", &json!({"text": text, "x": 0, "y": 0})).unwrap());
+        s.execute("edit.findReplace", &json!({"find": find, "replace": replace})).unwrap();
+        assert_eq!(s.doc().unwrap().node(t).unwrap().kind.text().unwrap().characters, want, "{text}: {find} -> {replace}");
+    }
+}
+
+#[test]
+fn find_replace_rejects_empty_find() {
+    let mut s = sess();
+    let t = id(&s.execute("text.create", &json!({"text": "cat", "x": 0, "y": 0})).unwrap());
+    assert!(s.execute("edit.findReplace", &json!({"find": "", "replace": "x"})).is_err());
+    assert_eq!(s.doc().unwrap().node(t).unwrap().kind.text().unwrap().characters, "cat");
+}
+
 #[test]
 fn components_and_instances_sync() {
     let mut s = sess();