Maybe this is also a fix for #247, #248 and #258. Supersedes #267.
Testcase:
Using match_prev_cmd strategy and with these lines in history:
echo '1^'
echo '2^'
echo '1^'
type:
echo (unexpected suggestion echo '1^' instead of echo '2^')
echo '1^1 (wrong suggestion echo '1^1echo '1^')
echo '1^# (error "bad math expression")