Re: [PATCH] gitweb: protect blob and diff output lines from controls.

[Jakub Narebski <jnareb@gmail.com>]

Junio C Hamano wrote:
> This reuses the quot_cec to protect blob and text diff output
> from leaking control characters.
> 
> Signed-off-by: Junio C Hamano <junkio@cox.net>
> ---
>  * requesting extra sets of eyeballs.

This changes the "blob" and "text diff" output somewhat, as earlier it 
used Control key Sequence (CS) representation for some non-whitespace 
control characters (not "\t' not '\n'), namely replacing form feed (FF) 
('\f', '\014') with ^L and escape (ESC) ('\e', '\033') with ^[.

And (what is not said in the commit message) it additionally esc_html 
some title elements (the subroutine should be I think named esc_attr).

The problems are:
1. First, esc_path should _not_ use subroutine which does it's own 
contol characters escaping. That was also a mistake I made in my patch.
Perhaps we should have some quot_html or to_html subroutine which does 
_only_ to_utf8 (decode from Encode module), escapeHTML and optionally 
s/ /&nbsp;/g conversion.

2. In my opinion CS is better than CEC for quoting/escaping control 
characters in the "bulk" output, namely "blob" output and "text 
diff" (patchset body) output. CEC is better for pathnames (which must 
fit in one line), and perhaps other one-liners; perhaps not. I'm not 
sure what quoting to choose for esc_attr, but there we could use even 
--no-control-chars quoting (replacing any control character by '?'); 
but perhaps in some cases like git_print_page_path subroutine CEC is 
better.

BTW. what had happened with to_qtext post?
-- 
Jakub Narebski