cause infinite loop in vim debug mode

[zhaocai]

Steps to reproduce

1. enter debug mode :breakadd func some_func
2. step to some func >step
3. now you are in the infinite loop. You will have to kill vim to quit.

error

151__trigger_or_fallback is going to be called endlessly

---

function some_func..<SNR>151__trigger_or_fallback..<SNR>151__trigger_or_fallback..<SNR>151__trigger_or_fallback..<SNR>151__trigger_or_fallback..<SNR>151__trigger_or_fallback..<SNR>151__trigger_or_fallback..<SNR>151__trigger_or_fallback..<
SNR>151__trigger_or_fallback..<SNR>151__trigger_or_fallback..<SNR>151__trigger_or_fallback..<SNR>151__trigger_or_fallback..<SNR>151__trigger_or_fallback..<SNR>151__trigger_or_fallback..<SNR>151__trigger_or_fallback..<SNR>151__trigger_or_fallback..<SNR>151__trigger_or_fallb
line 1: let nrule = mode() =~# '\v^(i|R|Rv)$' ? s:find_the_most_proper_rule_in_insert_mode(     s:available_nrules,     a:char   ) : s:find_the_most_proper_rule_in_command_line_mode(     s:available_nrules,     a:char,     getcmdline(),     getcmdpos(),     getcmdtype()
)
function some_func..<SNR>151__trigger_or_fallback..<SNR>151__trigger_or_fallback..<SNR>151__trigger_or_fallback..<SNR>151__trigger_or_fallback..<SNR>151__trigger_or_fallback..<SNR>151__trigger_or_fallback..<SNR>151__trigger_or_fallback..<
SNR>151__trigger_or_fallback..<SNR>151__trigger_or_fallback..<SNR>151__trigger_or_fallback..<SNR>151__trigger_or_fallback..<SNR>151__trigger_or_fallback..<SNR>151__trigger_or_fallback..<SNR>151__trigger_or_fallback..<SNR>151__trigger_or_fallback..<SNR>151__trigger_or_fallb
line 1: let nrule = mode() =~# '\v^(i|R|Rv)$' ? s:find_the_most_proper_rule_in_insert_mode(     s:available_nrules,     a:char   ) : s:find_the_most_proper_rule_in_command_line_mode(     s:available_nrules,     a:char,     getcmdline(),     getcmdpos(),     getcmdtype()
)
function some_func..<SNR>151__trigger_or_fallback..<SNR>151__trigger_or_fallback..<SNR>151__trigger_or_fallback..<SNR>151__trigger_or_fallback..<SNR>151__trigger_or_fallback..<SNR>151__trigger_or_fallback..<SNR>151__trigger_or_fallback..<
SNR>151__trigger_or_fallback..<SNR>151__trigger_or_fallback..<SNR>151__trigger_or_fallback..<SNR>151__trigger_or_fallback..<SNR>151__trigger_or_fallback..<SNR>151__trigger_or_fallback..<SNR>151__trigger_or_fallback..<SNR>151__trigger_or_fallback..<SNR>151__trigger_or_fallb
line 1: let nrule = mode() =~# '\v^(i|R|Rv)$' ? s:find_the_most_proper_rule_in_insert_mode(     s:available_nrules,     a:char   ) : s:find_the_most_proper_rule_in_command_line_mode(     s:available_nrules,     a:char,     getcmdline(),     getcmdpos(),     getcmdtype()
)  

[FuDesign2008]

I meet this problem too