[FIX] http,web,website_*: return the correct Content-Type for images

* = website_profile, website_slides

Before this commit, the returned Content-Type was not always correct, for
example if the image tool was changing the format, which happens when given
a BMP (converted to PNG), or other types being converted to JPEG.

The previous method `force_contenttype` was too specific and it wasn't available
in every controller. It didn't even need to be a controller method because it
didn't use self.

Now we create a generic helper to ease updating headers.
The Content-Type is only updated when it is safe to do. It is especially unsafe
for example for SVG files.

task-1958000
PR: #31811

1 files changed, 1 insertions, 1 deletions

diff --git a/addons/website_slides/controllers/main.py b/addons/website_slides/controllers/main.py
index 754edf27960..4da2d91f6a7 100644
--- a/addons/website_slides/controllers/main.py
+++ b/addons/website_slides/controllers/main.py
@@ -531,7 +531,7 @@ class WebsiteSlides(WebsiteProfile):
         image_base64 = tools.image_process(image_base64, (width, height), crop=crop)
 
         content = base64.b64decode(image_base64)
-        headers.append(('Content-Length', len(content)))
+        headers = http.set_safe_image_headers(headers, content)
         response = request.make_response(content, headers)
         response.status_code = status
         return response