Re: Strange behavior about pattern matching on manual pages [FIXED]

by <by_at_meetlost.com> wrote:

> Hi,
>
> I encounter a problem when viewing manuals via man(1) command.
>
> The case is simple, when I try to search something, I press ‘/’, and then input the pattern, If it got something in the page, it will direct me into the specified place, and then, I continue with ’n’, and it goes well.
> But the problem is, after a sequence of ’n’, the screen go to the end of the manual pages, and keeping press ’n’, I got annoying “...skipping...”, the page is full of skipping and parts of the end of the manual page.

Yes. This has been annoying me too - your email prompted me to finally work
on a fix for it!

Firstly, it isn't man(1) itself - man(1) uses more(1) as the pager.
more(1) is in itself actually the program less(1), running in "more
emulation mode".

And less(1) isn't FreeBSD native code - it's imported into the project
from http://www.greenwoodsoftware.com/less/

I noticed the very latest version of less(1) has been checked into
freebsd-current, and the issue still occurs there.

Anyway, the fix is two small patches to less(1), please let me know
if they work for you, and if you see any bad side-effects in man(1) /
more(1) and less(1) and I'll then try and get them applied upstream.

The patches have been tested against FreeBSD 11.1-STABLE and 12-CURRENT

cheers! Jamie

--- contrib/less/forwback.c.orig	2017-11-20 08:52:33.978356000 +0000
+++ contrib/less/forwback.c	2017-12-05 15:53:50.517550000 +0000
_at__at_ -255,7 +255,7 _at__at_
 		 * start the display after the beginning of the file,
 		 * and it is not appropriate to squish in that case.
 		 */
-		if ((first_time || less_is_more) &&
+		if ((first_time) &&
 		    pos == NULL_POSITION && !top_scroll && 
 #if TAGS
 		    tagoption == NULL &&
--- contrib/less/main.c.orig	2017-11-20 08:52:33.978356000 +0000
+++ contrib/less/main.c	2017-12-05 15:53:57.291394000 +0000
_at__at_ -168,7 +168,10 _at__at_
 	}
 
 	if (less_is_more)
+	{
 		no_init = TRUE;
+		scan_option("--tilde");
+	}
 
 #if EDITOR
 	editor = lgetenv("VISUAL");