[BUG][CRASH] Reverse search (extend) out of range vector access

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Version of Kakoune

Kakoune 2024.05.18-278-g92260722

Reproducer

Use this file:

1
1

1. ge # go to last char of last line
2. <a-/>1<ret> # select previous match before each selection
3. <a-N> # add a new selection with previous match before the main selection
4. <a-?> # extend to previous match before each selection

Outcome

Debug

Fatal error: assert failed "main < list.size()" at src/selection.cc:53

Release

SIGSEGV

Expectations

No response

Additional information

No response