Re: Bug in meta tag refresh code [with cause]

Hi,

On Sun, May 01, 2016 at 04:06:51PM +0100, Nick Warne wrote:
> I have been looking at this for about 5 hours now, and it has fried my
> brain.
> 
> Reading the code, and then reading the email thread about depreciated meta
> tag 'refresh', I agree with Dillo's actions.
> 
> But what I found was that on some sites (mine included), if there was a tag:
> 
> <meta http-equiv="refresh" content="15" />
> 
> Dillo reports and the warning message reports:
> 
> The author wanted you to go _here_ after 10 seconds.
> 
> What happens now is the link (_here_) gets appended with the refresh value,
> so for example:
> 
> www.example.com/refesh.html
> 
> becomes:
> 
> www.example.com/10  (or 15 or whatever the refresh value is).
> 
> I have found that if the meta tag is right:
> 
> <meta http-equiv="refresh" content="5;URL='./index.html'" />
> 
> then the code creates the right URL (but it's not seen as no warning is
> given.
> 
> html.cc  from line 3218
> 
> if the meta tag refresh is correct HTML on the web page, mr_url returns the
> correct path to the refresh.  If it isn't, then mr_url returns the value of
> the refresh - which fubars the warning messages link.
> 
> I tested this running dillo from the commandline with this insertion and
> testing the correct and wrong meta tags:
> 
>          }
>          /* Skip to anything after "URL=" or ";" if "URL=" is not found */
>          if ((p = dStriAsciiStr(content, "url=")))
>             content = p + strlen("url=");
>          else if ((p = strstr(content, ";")))
>             content = p + strlen(";");
>          /* Handle the case of a quoted URL */
>          if (*content == '"' || *content == '\'') {
>             if ((p = strchr(content + 1, *content)))
>                mr_url = dStrndup(content + 1, p - content - 1);
>             else
>                mr_url = dStrdup(content + 1);
>          } else {
>             mr_url = dStrdup(content);
>          }
> //nick
> printf ("%s\n", mr_url);
>          new_url = a_Html_url_new(html, mr_url, NULL, 0);
> //         new_url = a_Html_url_new(html, ".", NULL, 0);
> 
> 
> Not being very good with C++, I can't work out what goes wrong here - but it
> looks like that if 'URL=' or';' isn't found, then the code still looks for
> quotes - which does something to the string?
> 
> I have two pages you can test on - one with the proper meta tag, and one
> with out:
> 
> http://irpi.linicks.net:8080/static_simple.html  <- good
> 
> http://fishpi.linicks.net:8081/static_simple.html   <- bad - that shows the
> bug
> 
> If possible view both with that printf I put in - you can see what mr_url
> returns.

  Please try to be clear & concise.

  There's a bug, yes. You may try this:

diff -r c20e74568504 src/html.cc
--- a/src/html.cc       Sun May 01 10:49:17 2016 -0300
+++ b/src/html.cc       Sun May 01 23:26:48 2016 -0300
@@ -3220,6 +3220,8 @@ static void Html_tag_open_meta(DilloHtml
             content = p + strlen("url=");
          else if ((p = strstr(content, ";")))
             content = p + strlen(";");
+         else
+            content = "";
          /* Handle the case of a quoted URL */
          if (*content == '"' || *content == '\'') {
             if ((p = strchr(content + 1, *content)))


  @Johannes, does it look OK to you?

-- 
  Cheers
  Jorge.-