Performance problem with pasting. fish_wcwidth at fault? #5866
Description
I've seem to run into a performance problem with fish shell upon pasting a large amount of text.
Steps to reproduce: Copy about a pages worth of dmesg output, paste into terminal a couple of times, shell turns to a grinding halt, unable to CTRL+C while text is being pasted and sometimes afterwards I am also unable to escape.
I've investigated with perf and found the following results: https://paste.sr.ht/%7Ekeli/c99256cfc926a7f7d7b6aa869c6884c94f2403c1
I can supply the entire perf record file if needed.
Perf reports that fish_wcwidth is using about half the cpu-time, this is evident when looking at htop while the text is being pasted, the cpu tends to go to 100%.
Fish version: 3.0.2
Terminal emulator: Alacritty 0.3.2
Kernel 5.0.13-arch1-1-ARCH