Fix SmoLStrBuilder pushing null bytes on heap spill
diff --git a/CHANGELOG.md b/CHANGELOG.md
index c1346a2..41f1377 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,10 @@
# Changelog
+## 0.3.2 - 2024-10-23
+
+- Fix `SmolStrBuilder::push` incorrectly padding null bytes when spilling onto the heap on a
+ multibyte character push
+
## 0.3.1 - 2024-09-04
- Fix `SmolStrBuilder` leaking implementation details
diff --git a/src/lib.rs b/src/lib.rs
index d00ec98..bf88f57 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -763,7 +763,7 @@
let mut heap = String::with_capacity(new_len);
// copy existing inline bytes over to the heap
// SAFETY: inline data is guaranteed to be valid utf8 for `old_len` bytes
- unsafe { heap.as_mut_vec().extend_from_slice(buf) };
+ unsafe { heap.as_mut_vec().extend_from_slice(&buf[..*len]) };
heap.push(c);
self.0 = SmolStrBuilderRepr::Heap(heap);
}
diff --git a/tests/test.rs b/tests/test.rs
index 81bccf1..96b8b8f 100644
--- a/tests/test.rs
+++ b/tests/test.rs
@@ -255,6 +255,7 @@
assert_eq!(a, smol_str::format_smolstr!("{}", a));
}
}
+
#[test]
fn test_builder_push_str() {
//empty
@@ -290,6 +291,14 @@
let s = builder.finish();
assert!(s.is_heap_allocated());
assert_eq!("a".repeat(46), s);
+
+ // heap push on multibyte char
+ let mut builder = SmolStrBuilder::new();
+ builder.push_str("ohnonononononononono!");
+ builder.push('🤯');
+ let s = builder.finish();
+ assert!(s.is_heap_allocated());
+ assert_eq!("ohnonononononononono!🤯", s);
}
#[test]
