Delete the disused & unspecced identicon functionality

changelog.d/4106.removal

@@ -0,0 +1 @@
+The disused and un-specced identicon generator has been removed.

synapse/handlers/register.py

@@ -254,9 +254,6 @@ def register(
             except Exception as e:
                 logger.error("Failed to join new user to %r: %r", r, e)
 
-        # We used to generate default identicons here, but nowadays
-        # we want clients to generate their own as part of their branding
-        # rather than there being consistent matrix-wide ones, so we don't.
         defer.returnValue((user_id, token))
 
     @defer.inlineCallbacks

synapse/python_dependencies.py

@@ -51,7 +51,6 @@
     "daemonize>=2.3.1": ["daemonize"],
     "bcrypt>=3.1.0": ["bcrypt>=3.1.0"],
     "pillow>=3.1.2": ["PIL"],
-    "pydenticon>=0.2": ["pydenticon"],
     "sortedcontainers>=1.4.4": ["sortedcontainers"],
     "psutil>=2.0.0": ["psutil>=2.0.0"],
     "pysaml2>=3.0.0": ["saml2"],

synapse/rest/media/v1/media_repository.py

@@ -45,7 +45,6 @@
 from .config_resource import MediaConfigResource
 from .download_resource import DownloadResource
 from .filepath import MediaFilePaths
-from .identicon_resource import IdenticonResource
 from .media_storage import MediaStorage
 from .preview_url_resource import PreviewUrlResource
 from .storage_provider import StorageProviderWrapper
@@ -769,7 +768,6 @@ def __init__(self, hs):
         self.putChild(b"thumbnail", ThumbnailResource(
             hs, media_repo, media_repo.media_storage,
         ))
-        self.putChild(b"identicon", IdenticonResource())
         if hs.config.url_preview_enabled:
             self.putChild(b"preview_url", PreviewUrlResource(
                 hs, media_repo, media_repo.media_storage,