vim: Fix snapshot out of bounds indexing (#42969)

Lukas Wirth created 

Fixes ZED-38X

Release Notes:

- N/A

Change summary

crates/vim/src/normal/increment.rs | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

Detailed changes

crates/vim/src/normal/increment.rs 🔗 

@@ -211,7 +211,7 @@ fn find_target(
     let mut pre_char = String::new();
 
     // Backward scan to find the start of the number, but stop at start_offset
-    for ch in snapshot.reversed_chars_at(offset + 1) {
+    for ch in snapshot.reversed_chars_at(offset + if offset < snapshot.len() { 1 } else { 0 }) {
         // Search boundaries
         if offset == 0 || ch.is_whitespace() || (need_range && offset <= start_offset) {
             break;