Re: [PATCH/RFC] gitweb: highlight: strip non-printable characters via col(1)

["J.H." <warthog9@eaglescrag.net>]

On 08/16/2011 11:16 AM, Christopher M. Fuhrman wrote:
> From: "Christopher M. Fuhrman" <cfuhrman@panix.com>
> 
> The current code, as is, passes control characters, such as form-feed
> (^L) to highlight which then passes it through to the browser.  This
> will cause the browser to display one of the following warnings:
> 
> Safari v5.1 (6534.50) & Google Chrome v13.0.782.112:
> 
>   This page contains the following errors:
> 
>   error on line 657 at column 38: PCDATA invalid Char value 12
>   Below is a rendering of the page up to the first error.
> 
> Mozilla Firefox 3.6.19 & Mozilla Firefox 5.0:
> 
>    XML Parsing Error: not well-formed
>    Location:
>    http://path/to/git/repo/blah/blah
> 
> Both errors were generated by gitweb.perl v1.7.3.4 w/ highlight 2.7
> using arch/ia64/kernel/unwind.c from the Linux kernel.
> 
> Strip non-printable control-characters by piping the output produced
> by git-cat-file(1) to col(1) as follows:
> 
>   git cat-file blob deadbeef314159 | col -bx | highlight <args>

So my only real concern here is that `col` itself is going to munge
whitespace.  Quoting from the col man page:

	[...] and replaces white-space characters with tabs where
	    possible. [...]

Have you actually run into a situation where something like ^L was
present in a blob that was being passed to highlight?

- John