# URL parsing with "?" does not work [duplicate]

An answer of mine includes an URL with a ?, which is not correctly parsed. I think it should be.

Actually, I wanted to include the image that is autogenerated from the URL, to show a point of my answer, this did also not work.

It is not the question mark that is at issue there. You need to properly quote your URL parameters; it is the backslash and braces that cause the query parameter to be ignored.

Rather than use:

https://latex.codecogs.com/png.latex?\sum^{i%3D\infty}_{i%3D0}x_{i}}


use

https://latex.codecogs.com/png.latex?%5Csum%5E%7Bi%3D%5Cinfty%7D_%7Bi%3D0%7Dx_%7Bi%7D%7D


The backslash, caret and braces are all quoted now, not just the = equals signs.

This is recognised as a proper URL: https://latex.codecogs.com/png.latex?%5Csum%5E%7Bi%3D%5Cinfty%7D_%7Bi%3D0%7Dx_%7Bi%7D%7D

and is usable as an image:

$\sum^{i=\infty}_{i=0}x_{i}}$

• Thanks for the answer. I wasn't aware of this. Could the "proper" quoting be implemented in the URL parser?
– Habi
Dec 1 '14 at 9:40
• @Habi: no, because then any sentence ending in a URL and a question mark would pull in the rest of the post. That's what proper URL quoting is for, so that URLs can be properly recognised and handled. Dec 1 '14 at 9:41
• That makes sense. This makes my orginal answer less usable then, since a simple copy-paste link for embedding in a forum was asked for :)
– Habi
Dec 1 '14 at 9:44
• @Habi: you need to include a online URL encoding step in that case. Dec 1 '14 at 9:47