Jakub Narębski[Forgot to hit Reply-to-all instead of Reply. Andrew, I'm sorry for duplicate email]
On Sat, Mar 29, 2014 at 2:53 PM, Andrew Keller <andrew@kellerfarm.com> wrote:
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> > When formatting a diff header line, be sure to escape the raw output from git > for use as HTML. This ensures that when "problem characters" (&, <, >, ?, etc.) > exist in filenames, gitweb displays them as text, rather than letting the > browser interpret them as HTML.
Actually gitweb tries to do the right thing, and in most cases it does HTML escaping correctly. The problem is only with *binary* files (this fact should IMHO have been mentioned in commit message).
This issue is caused by two problems / errors. First, gitweb misclassify "Binary files a/foo and b/bar differ" as diff header, while it is untypical but it is diff contents. Second, gitweb doesn't HTML-escape unknown diff headers, assuming that it knows about all possible types.
I have had those changes in my git repository, but I do not know if I have pushed it before the PC went down, and if I have it in backup.
> > Reported-by: Dongsheng Song <dongsheng.song@gmail.com> > Signed-off-by: Andrew Keller <andrew@kellerfarm.com>
Thank you for your work.
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> --- > Steps to reproduce: > > 1) Create a repository that contains a commit that adds a file: > * with an ampersand in the filename > * with binary contents > 2) Make the repository visible to gitweb > 3) In gitweb, navigate to the page that shows the diff for the commit > that added the file > > Behavior without patch:
Page contains unescaped '&' instead of '&'
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> Page stops rendering when it gets to one of > the instances of the filename (in the diff header, to be specific), and > a light-red box appears a the top of the page, saying something like > this: > > This page contains the following errors: > > error on line 67 at column 22: xmlParseEntityRef: no name > > Below is a rendering of the page up to the first error. > > > (This particular error is what you get with an unescaped ampersand)
This is caused by the fact that some browsers use strict XML validation mode when receiving 'application/xml+xhtml' contents, and not 'text/html'. So one might not notice it...
> Behavior with patch: You see the ampersand in the file name, and the > page renders as one would expect.
A question: it does not escapes HTML twice, i.e. you don't see '&' in rendered output ('&amp;' in page source)?
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> Other notes: > > Several helper methods exist for escaping HTML, and I was unsure > about which one to use. Although this patch fixes the problem, > it is possible that it may be more correct to use, for example, the > 'esc_html' helper method instead of interacting with $cgi directly.
It is preferred to use esc_html instead of $cgi->escapeHTML. Even better use esc_path to escape pathnames.
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> The first hunk in the diff seems to be all that's required to experience > the good behavior, however upon inspecting the code, it seems > prudent to also include the second one. It's a nearby section of code, > doing similar work, and is called from the same function as the > former, and with similar arguments.
I wonder if it would not interfere with processing of diff contents by gitweb, for example adding links to pre-image and post-image version of a file.
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> gitweb/gitweb.perl | 4 ++++
> 1 files changed, 4 insertions(+), 0 deletions(-)
>
> diff --git a/gitweb/gitweb.perl b/gitweb/gitweb.perl
> index 79057b7..6c559f8 100755
> --- a/gitweb/gitweb.perl
> +++ b/gitweb/gitweb.perl
> @@ -2223,6 +2223,8 @@ sub format_git_diff_header_line {
> my $diffinfo = shift;
> my ($from, $to) = @_;
>
> + $line = $cgi->escapeHTML($line);
> +
> if ($diffinfo->{'nparents'}) {
> # combined diff
> $line =~ s!^(diff (.*?) )"?.*$!$1!;
> @@ -2259,6 +2261,8 @@ sub format_extended_diff_header_line {
> my $diffinfo = shift;
> my ($from, $to) = @_;
>
> + $line = $cgi->escapeHTML($line);
> +
> # match <path>
> if ($line =~ s!^((copy|rename) from ).*$!$1! && $from->{'href'}) {
> $line .= $cgi->a({-href=>$from->{'href'}, -class=>"path"},I'd have to examine code flow to check where it lands...
-- Jakub Narębski