text: Downgrade some more offset panics to error logs (#43925)

Lukas Wirth created 15 hours ago

Release Notes:

- N/A *or* Added/Fixed/Improved ...

Change summary

crates/rope/src/chunk.rs |  6 +++++-
crates/rope/src/rope.rs  | 16 ++++++++++++----
crates/text/src/text.rs  | 28 +++++++++++++++++++---------
3 files changed, 36 insertions(+), 14 deletions(-)

Detailed changes

crates/rope/src/chunk.rs

@@ -220,7 +220,11 @@ impl<'a> ChunkSlice<'a> {
                 range.start = self.text.ceil_char_boundary(range.start);
             }
             if !self.assert_char_boundary::<false>(range.end) {
-                range.end = self.text.floor_char_boundary(range.end);
+                range.end = if range.end < range.start {
+                    range.start
+                } else {
+                    self.text.floor_char_boundary(range.end)
+                };
             }
             let mask = (1 as Bitmap)
                 .unbounded_shl(range.end as u32)

crates/rope/src/rope.rs

@@ -50,23 +50,31 @@ impl Rope {
 
     #[track_caller]
     #[inline(always)]
-    pub fn assert_char_boundary(&self, offset: usize) {
+    pub fn assert_char_boundary<const PANIC: bool>(&self, offset: usize) -> bool {
         if self.chunks.is_empty() && offset == 0 {
-            return;
+            return true;
         }
         let (start, _, item) = self.chunks.find::<usize, _>((), &offset, Bias::Left);
         match item {
             Some(chunk) => {
                 let chunk_offset = offset - start;
-                chunk.assert_char_boundary::<true>(chunk_offset);
+                chunk.assert_char_boundary::<PANIC>(chunk_offset)
             }
-            None => {
+            None if PANIC => {
                 panic!(
                     "byte index {} is out of bounds of rope (length: {})",
                     offset,
                     self.len()
                 );
             }
+            None => {
+                log::error!(
+                    "byte index {} is out of bounds of rope (length: {})",
+                    offset,
+                    self.len()
+                );
+                false
+            }
         }
     }
 

crates/text/src/text.rs

@@ -2435,16 +2435,22 @@ impl BufferSnapshot {
         self.anchor_at_offset(position.to_offset(self), bias)
     }
 
-    fn anchor_at_offset(&self, offset: usize, bias: Bias) -> Anchor {
+    fn anchor_at_offset(&self, mut offset: usize, bias: Bias) -> Anchor {
         if bias == Bias::Left && offset == 0 {
             Anchor::min_for_buffer(self.remote_id)
-        } else if bias == Bias::Right && offset == self.len() {
+        } else if bias == Bias::Right
+            && ((cfg!(debug_assertions) && offset >= self.len()) || offset == self.len())
+        {
             Anchor::max_for_buffer(self.remote_id)
         } else {
-            if cfg!(debug_assertions) {
-                self.visible_text.assert_char_boundary(offset);
-            } else if offset > self.visible_text.len() {
-                panic!("offset {} is out of bounds", offset)
+            if self
+                .visible_text
+                .assert_char_boundary::<{ cfg!(debug_assertions) }>(offset)
+            {
+                offset = match bias {
+                    Bias::Left => self.visible_text.floor_char_boundary(offset),
+                    Bias::Right => self.visible_text.ceil_char_boundary(offset),
+                };
             }
             let (start, _, item) = self.fragments.find::<usize, _>(&None, &offset, bias);
             let fragment = item.unwrap();
@@ -3136,10 +3142,14 @@ impl ToOffset for Point {
 
 impl ToOffset for usize {
     fn to_offset(&self, snapshot: &BufferSnapshot) -> usize {
-        if cfg!(debug_assertions) {
-            snapshot.as_rope().assert_char_boundary(*self);
+        if snapshot
+            .as_rope()
+            .assert_char_boundary::<{ cfg!(debug_assertions) }>(*self)
+        {
+            snapshot.as_rope().floor_char_boundary(*self)
+        } else {
+            *self
         }
-        *self
     }
 }