String comparison complains about ampersands

[rigrig]

Basically I'm doing something like this, but getting a warning:

#debug all
...
#math isExample {{http://example.com?foo=1&bar=2} == {%*example.com%*}}
    #math isExample {{http://example.com?foo=1&bar=2} == {%*example.com%*}}
#WARNING: FOUND &bar. USE &{bar} INSTEAD?
#MATH: VARIABLE {isExample} HAS BEEN SET TO {1}.

It's coming from substitute.c, there are two checks, I added some debug output and the root == NULL one fired here.

I guess it makes sense to complain if you just type this:

#math test {{&a} == {}}
    #math test {{&a} == {}}
#WARNING 1: FOUND &a in '&a} == {}'. USE &{a} INSTEAD?
#MATH: VARIABLE {test} HAS BEEN SET TO {0}.

But my actual code is a bunch of #if statements that decide whether to substitute URL-like strings with clickable links, so it is triggered by %0 containing the offending character: (thus hard to work around, unless I'm doing something wrong here?)

#nop URLs: regex from https://regexr.com/3e6m0;
#sub {{(http(s)?:\/\/.)?(www\.)?[-a-zA-Z0-9@:%._\+~#=]{2,256}\.[a-z]{2,6}\b([-a-zA-Z0-9@:%_\+.~#?&//=]*)}}
    {@url_link{%0}};
#nop Link to open URL: @url_link{url};
#function {url_link} {
   #if {"%0" == "%*..%*"} #return {%0}; #nop probably not an URL after all <-- WARNING;
   ...
   #return <clickable link>;
}

I'm running 2.02.12b, looks like this warning was added in 2.02.04.

[scandum]

That's pretty annoying and I reckon that warning has outlived its usefulness. I've removed the warning in the beta.

[rigrig]

Great, thanks!