mirror of
https://github.com/junegunn/fzf.git
synced 2025-11-16 07:13:48 -05:00
There is an edge-case in FuzzyMatchV1 during backward scan, related to
normalization: if string is initially denormalized (e.g. Unicode symbol),
backward scan will proceed further to the next char; however, when the
score is computed, the string is normalized first, then scanned based on
the pattern. This leads to accessing pattern index increment, which
itself leads to out-of-bound index access, resulting in a panic.
To illustrate the process, here's the sequence of operations when search
is perfored:
1. during backward scan by "minim" pattern
```
xxxxx Minímal example
^^^^^^^^^^^^
||||||||||||
miniiiiiiiim <- compute score for this substring
```
2. during compute score by "minim" pattern
```
Minímal exam
minimal exam <- normalize chars before computing the score
^^^^^^
||||||
minim <- at this point the pattern is already fully scanned and index
is out-of-the-bound
```
In this commit the char is normalized during backward scan, to detect
properly the boundaries for the pattern.