I have reported these bugs to Denys Vlasenko who maintains Busybox. But I thought that I should also report them here so that folks will be aware of the problem and don't make the mistake of assuming that the less function of Busybox provides correct information.
Here is an excerpt from my bug report to Denys Vlasenko:
I didn't do any serious testing of the less function. This is just stuff that I tripped over. So it may well have other bugs.Here are 3 bugs that I've found with the less function of BusyBox v1.19.3:
---------- Bug A ----------
busybox less splits long lines into multiple lines. This creates the
following problems:
1. The line numbers reported on the status line by the = command and the
-M option are incorrect beyond the first split line.
2. Search will not find words that have been split.
---------- Bug B ----------
The busybox less function does not reset the start position of search when
user moves or jumps to another place in the file.
The real less utility allows the user to move or jump to any place in the
file and continue searching from there with the n command. For instance,
a user who is midway through a file may begin searching for a word, find
matches (if any) in the remaining lines, then press p to jump to the
beginning of the file and continue to use the n command to find matches
(if any) in the first part of the file. Thus the user can effectively
wrap-around the search.
This is not possible with busybox less. Once the last match in the file
has been found, no others may be found until the user starts a new search
or searches backwards. So a user who is midway through a file can find
matches (if any) in the remaining lines, but to then find matches (if any)
at the beginning of the file she must either use SHIFT-N to back-up
through all the previously found matches and continue searching backward
to the start of the file, or she must move to the beginning of the file
and type the search pattern again.
---------- Bug C ----------
When used with the -S option, busybox less chops long lines, but neither
RightArrow nor ESC-) scrolls horizontally to allow reading the whole line.
---------------------------
(While looking to see if this had been reported before, I came across a post from someone who had a different problem with Busybox less: [Wary 030] BusyBox less fails in ipython)
For my own use, I simply copied the real less from my tried-and-true Puppy 4.3.1. I see that the real less is also in the pet_packages-wary5 repository.
But if one is unaware of the problem, and so has not yet installed the real less, there can be a fair bit of frustration before one realizes what is happening: hunting for strings that Busybox less claims not to exist, or finding line 1234 in Busybox less then seeing a different line 1234 when the file is loaded into an editor.
and looked at xerrs.log afterwards.