Re: [PATCH 2/3] lisp/progmodes/etags.el don't (forward-char) as it's overriden next line

[Konstantin Kharlamov <hi-angel@yandex.ru>]

В Вс, мар 17, 2019 at 11:40 ПП (PM), Eli Zaretskii 
<eliz@gnu.org> написал:
>>  Date: Sun, 17 Mar 2019 23:27:30 +0300
>>  From: Konstantin Kharlamov <hi-angel@yandex.ru>
>>  Cc: emacs-devel@gnu.org
>> 
>>  >>  Okay, so: ^M appears in selective-display-mode only in the end 
>> of a
>>  >>  line.
>>  >
>>  > No, ^M _replaces_ newline characters, so what was previously 
>> several
>>  > lines is now a single long line.
>> 
>>  Sure, but after the patch we don't match the whole line anymore. We
>>  only match the tag. We don't care if it's at the beginning of the 
>> line
>>  or in the middle of it. We only look for the tag. So we don't care 
>> if
>>  line has a newline character or ^M.
> 
> But that's incorrect: a tag in a tags table always begins at the
> beginning of a line, so it must be a search anchored at the beginning
> of the line.  And in selective-display mode ^M counts as the beginning
> of a line.

Great, now that we established that part, to reply your question why we 
don't care about the beginnging of the line let me quote my other mail:

 > The pattern that this functions searches for determines the tag 
uniquely. But here's a catch: no programming language creates distinc 
entities (ones that end up in the tag), based only on trailing space. 
I.e. "foo()" and " foo() " always refer to the same thing.
 >
 > So this change gives 2 improvements:
 > 1. Emacs gonna stop failing finding a tag when someone simply 
reindented the sources
 > 2. As a side effect, this works around a problem, when a 
tags-generating program trimmed the whitespace (the commit has a link 
to anjuta-tags bugreport about that).