bug#44983: Truncate long lines of grep output

[Andreas Schwab <schwab@linux-m68k.org>]

On Dez 01 2020, Eli Zaretskii wrote:

>> From: Dmitry Gutov <dgutov@yandex.ru>
>> Date: Tue, 1 Dec 2020 17:02:09 +0200
>> 
>> >>> This is a bug problem - often grep output lines are so long
>> >>> that Emacs freezes, so need to kill the process.  Updating
>> >>> manually ignored-files every time a new file causes freeze
>> >>> is very unreliable and time-consuming workaround.
>> >>
>> >> And a non-obvious one (for an average user).
>> >>
>> >> Is the same problem exhibited by commands using the Xref UI? I don't
>> >> remember seeing it, but of course our projects can be very different.
>> > 
>> > No difference from grep, Xref output has the same problem.
>> 
>> Perhaps (setq truncate-lines t) could help in that case?
>
> Not necessarily, because the truncated parts are still in the buffer,
> and the display code which is slow in that case basically moves
> through the buffer one character at a time in many cases.  Only some
> specific scenarios (read: a small number of commands) can jump to the
> next physical line disregarding the truncated parts.

But moving though the buffer is much faster than rendering it.

Andreas.

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Andreas Schwab, schwab@linux-m68k.org
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