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

Release Notes:

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

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
+            }
         }
     }