[PATCH v2 15/15] render: adapt for providing extra filter args for plain

[John Keeping]

On Mon, Jun 18, 2018 at 10:58:31AM +0800, Andy Green wrote:
> This changes the render filter exec part to provide a second
> and third argument, which are used by md2html to fix up the url
> path for "plain" for the repo, eg, "/cgit/plain/" and
> "?h=mybranch", as required by the modifications to md2html in
> the previous patches.
> 
> The combination means cgit becomes able to serve assets using
> markdown urls starting from the repo root dir, without mentioning
> any virtual url part specific to a cgit or other web rendering
> instance, while respecting the version context.
> 
> Eg, continuing the example of the arguments being
> "/cgit/plain/" and "?h=mybranch" from above, if the markdown has
> 
> ![overview](./doc-assets/overview.png)
> 
> the img src will be fixed up to
> 
> "/cgit/plain/doc-assets/overview.png?h=mybranch"
> 
> If the same document is viewed from a different rev in cgit, the
> processed markdown url will change to match the cgit context, even
> though the markdown relative URL is the same for all versions.
> 
> Signed-off-by: Andy Green <andy at warmcat.com>
> ---
>  filter.c  |    5 ++++-
>  ui-tree.c |   13 +++++++++++--
>  2 files changed, 15 insertions(+), 3 deletions(-)
> 
> diff --git a/filter.c b/filter.c
> index 4ae4aaa..7c1f188 100644
> --- a/filter.c
> +++ b/filter.c
> @@ -424,6 +424,10 @@ struct cgit_filter *cgit_new_filter(const char *cmd, filter_type filtertype)
>  			argument_count = 12;
>  			break;
>  
> +		case RENDER:
> +			argument_count = 3;
> +			break;
> +
>  		case EMAIL:
>  			argument_count = 2;
>  			break;
> @@ -434,7 +438,6 @@ struct cgit_filter *cgit_new_filter(const char *cmd, filter_type filtertype)
>  
>  		case SOURCE:
>  		case ABOUT:
> -		case RENDER:
>  			argument_count = 1;
>  			break;
>  
> diff --git a/ui-tree.c b/ui-tree.c
> index 9f59d18..5bbe30d 100644
> --- a/ui-tree.c
> +++ b/ui-tree.c
> @@ -102,16 +102,25 @@ static void print_buffer(const char *basename, char *buf, unsigned long size)
>  }
>  
>  static void render_buffer(struct cgit_filter *render, const char *name,
> -		char *buf, unsigned long size)
> +			  char *buf, unsigned long size)
>  {
>  	char *filter_arg = xstrdup(name);
> +	char *repo_url = cgit_repourl(ctx.repo->url);
> +	struct strbuf sb_plain = STRBUF_INIT, sb_postfix = STRBUF_INIT;
> +
> +	strbuf_addf(&sb_plain, "%splain/", repo_url);

This doesn't always work (if we don't have cfg.virtual_root set it's
wrong).

The logic in ui-shared.c::reporevlink() does the right thing, and it
might be possible to extract a helper function but we may just have to
replicate it since that version generates the URL as an HTML attribute
value.

> +	if (ctx.qry.head)
> +		strbuf_addf(&sb_postfix, "?h=%s", ctx.qry.head);
> +	free(repo_url);
>  
>  	html("<div class='blob'>");
> -	cgit_open_filter(render, filter_arg);
> +	cgit_open_filter(render, filter_arg, sb_plain.buf, sb_postfix.buf);
>  	html_raw(buf, size);
>  	cgit_close_filter(render);
>  	html("</div>");
>  
> +	strbuf_release(&sb_plain);
> +	strbuf_release(&sb_postfix);
>  	free(filter_arg);
>  }
>