Markdown Alt text on images not recognized on some cases

Feedback Bugs
1

I’ve noticed that on some of the images on my blog, the alt text (i.e. the part between ![ and ](https://my-image-url.png) is missing from the generated HTML code.

To be more precise, consider the following Markdown:
![Capture d'écran de Our House de GameGrumps (url)](https://système.pointecouteau.com/writeas/superliminal.png)

When I save my post with this code, it is correctly converted:
<img src="https://syst%C3%A8me.pointecouteau.com/writeas/superliminal.png" alt="Capture d'écran de Our House de GameGrumps (url)">

Howewer, for those two Markdown sentences, the generated HTML omits the “alt” tag entirely for some reason:

  • ![Capture d'écran de "Our House" de GameGrumps](https://système.pointecouteau.com/writeas/superliminal.png)
  • ![Capture d'écran de Our House de GameGrumps (https://www.youtube.com/watch?v=k55FYtqtXXU)](https://système.pointecouteau.com/writeas/superliminal.png)

Why is that? Do I need to insert some sort of escape character before quotation marks or slashes?