fix: guard setCursor against nil and fallback getNextCol on regex miss#2
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vann-at-cpcp-dot-tw wants to merge 1 commit into
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fix: guard setCursor against nil and fallback getNextCol on regex miss#2vann-at-cpcp-dot-tw wants to merge 1 commit into
vann-at-cpcp-dot-tw wants to merge 1 commit into
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When editing text containing certain multi-byte or edge-case characters,
pressing insert-mode motion keys (e.g. Right arrow) could crash with:
E5108: attempt to perform arithmetic on local 'col' (a nil value)
at setCursor (core.lua:94)
called from rmbMotionRight.move (core.lua:533)
Root cause:
- getNextCol uses vim.regex("\\%Xc.") which can miss in edge cases,
returning `nil` via `return to and to + 1`.
- setCursor then does `col - 1` on nil and throws.
Fix:
1. setCursor: early-return when row/col is nil (defense-in-depth,
covers all motion paths that pass nil through).
2. getNextCol: fallback to the naive `col + 1` on regex miss
(matches the author's own commented-out `col_target = col + 1`
intent at rmbMotionRight, keeps cursor moving instead of no-op).
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Summary
Fixes a crash in insert-mode motions when the cursor is near certain multi-byte / edge-case characters.
Reproduction
Open a markdown file, paste text containing CJK or special characters, then press
<Right>/<Left>in insert mode. Get:```
E5108: Error executing lua: ...lua/rambo/core.lua:94: attempt to perform arithmetic on local 'col' (a nil value)
stack traceback:
...lua/rambo/core.lua:94: in function 'setCursor'
...lua/rambo/core.lua:533: in function 'move'
...lua/rambo/core.lua:1169: in function <...>
```
Root cause
`getNextCol` uses `vim.regex("\\%Xc.")` which can miss at edge byte positions, returning `nil` via `return to and to + 1`. `setCursor` then does `col - 1` on nil → crash.
Fix
`getPrevCol` returning `nil` at line-start is left alone — it's a meaningful boundary; the `setCursor` guard makes it safe.
Test plan
🤖 Generated with Claude Code