refactor(vim): avoid overlapping edits on change surrounds

Update `Vim.change_surround` in order to ensure that there's no
overlapping edits by keeping track of where the open string range ends
and ensuring that the closing string range start does not go lower than
the open string range end.

Author: dinocosta

crates/vim/src/surrounds.rs

@@ -282,7 +282,7 @@ impl Vim {
                             // that the end replacement string does not exceed
                             // this value. Helpful when dealing with newlines.
                             let mut edit_len = 0;
-                            let mut forward_end: Option<usize> = None;
+                            let mut open_range_end = 0;
                             let mut chars_and_offset = display_map
                                 .buffer_chars_at(range.start.to_offset(&display_map, Bias::Left))
                                 .peekable();
@@ -291,11 +291,11 @@ impl Vim {
                                 if ch.to_string() == will_replace_pair.start {
                                     let mut open_str = pair.start.clone();
                                     let start = offset;
-                                    let mut end = start + 1;
+                                    open_range_end = start + 1;
                                     while let Some((next_ch, _)) = chars_and_offset.next()
-                                        && next_ch.to_string() == " "
+                                        && next_ch == ' '
                                     {
-                                        end += 1;
+                                        open_range_end += 1;
 
                                         if preserve_space {
                                             open_str.push(next_ch);
@@ -306,10 +306,9 @@ impl Vim {
                                         open_str.push(' ');
                                     };
 
-                                    edit_len = end - start;
-                                    edits.push((start..end, open_str));
+                                    edit_len = open_range_end - start;
+                                    edits.push((start..open_range_end, open_str));
                                     anchors.push(start..start);
-                                    forward_end = Some(end);
                                     break;
                                 }
                             }
@@ -325,10 +324,9 @@ impl Vim {
                                     let mut start = offset;
                                     let end = start + 1;
                                     while let Some((next_ch, _)) = reverse_chars_and_offsets.next()
-                                        && (next_ch.to_string() == " "
-                                            && forward_end
-                                                .map_or(true, |open_end| start > open_end))
+                                        && next_ch == ' '
                                         && close_str.len() < edit_len - 1
+                                        && start > open_range_end
                                     {
                                         start -= 1;