browse: Fix a couple of spotted issues in the UI

Ensure only source code is highlighted in content views

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Fix breadcrumb link for root directory in revision view.

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Rework "Download" button in content views to offer the same feature as the "Raw File" one except the content will be downloaded and saved to disk instead of rendering it in the browser.

Fixes #4834 (closed).

swh/web/browse/views/revision.py

@@ -392,7 +392,7 @@ def revision_browse(request: HttpRequest, sha1_git: str) -> HttpResponse:
         dir_id = revision["directory"]
 
     if dir_id:
-        path = "" if path is None else (path + "/")
+        path = "" if not path else (path + "/")
         dirs, files = get_directory_entries(dir_id)
 
     revision_metadata = RevisionMetadata(
@@ -445,7 +445,7 @@ def revision_browse(request: HttpRequest, sha1_git: str) -> HttpResponse:
             "url": reverse(
                 "browse-revision",
                 url_args={"sha1_git": sha1_git},
-                query_params=query_params,
+                query_params={**query_params, **{"path": ""}},
             ),
         }
     )
@@ -463,9 +463,9 @@ def revision_browse(request: HttpRequest, sha1_git: str) -> HttpResponse:
         )
 
     vault_cooking = {
-        "directory_context": False,
-        "directory_swhid": None,
-        "revision_context": True,
+        "directory_context": not bool(content_data),
+        "directory_swhid": f"swh:1:dir:{revision['directory']}",
+        "revision_context": not bool(content_data),
         "revision_swhid": f"swh:1:rev:{sha1_git}",
     }