Percent encode artifact names in fetch-content

Previously, trying to use fetch-content for an artifact that had a space
in it would result in errors like `Download failed: URL can't contain
control characters. '[...]' (found at least ' ')`

This commit changes fetch-content so we encode the artifact name when
building the download URL instead of putting it verbatim in the URL.
Because we're later reusing the URL to get the base name to know which
file to write, we now decode the basename so the resulting file doesn't
contain percent encoded characters.

Before:

```
$ export MOZ_FETCHES='[{"task":"FNpL6lwoTVyuWE3wgNeuUw","artifact":"public/Twilight Princess-0.2.3.apworld","extract":false}]'
$ uv run python3 src/taskgraph/run-task/fetch-content task-artifacts -d /tmp/fetch-test
attempt 1/5
Downloading https://taskcluster.bananium.fr/api/queue/v1/task/DBFKDCtCSi6gg35xPqZHOA/artifacts/public/Twilight Princess-0.3.0.apworld to /tmp/fetch-test/Twilight Princess-0.3.0.apworld
Downloading https://taskcluster.bananium.fr/api/queue/v1/task/DBFKDCtCSi6gg35xPqZHOA/artifacts/public/Twilight Princess-0.3.0.apworld
Download failed: URL can't contain control characters. '/api/queue/v1/task/DBFKDCtCSi6gg35xPqZHOA/artifacts/public/Twilight Princess-0.3.0.apworld' (found at least ' ')
sleeping for 60.00s (attempt 1/5)
```

After:

```
$ export MOZ_FETCHES='[{"task":"FNpL6lwoTVyuWE3wgNeuUw","artifact":"public/Twilight Princess-0.2.3.apworld","extract":false}]'
$ uv run python3 src/taskgraph/run-task/fetch-content task-artifacts -d /tmp/fetch-test
attempt 1/5
Downloading https://taskcluster.bananium.fr/api/queue/v1/task/DBFKDCtCSi6gg35xPqZHOA/artifacts/public/Twilight%20Princess-0.3.0.apworld to /tmp/fetch-test/Twilight Princess-0.3.0.apworld
Downloading https://taskcluster.bananium.fr/api/queue/v1/task/DBFKDCtCSi6gg35xPqZHOA/artifacts/public/Twilight%20Princess-0.3.0.apworld
https://taskcluster.bananium.fr/api/queue/v1/task/DBFKDCtCSi6gg35xPqZHOA/artifacts/public/Twilight%20Princess-0.3.0.apworld resolved to 155321 bytes with sha256 77c8ccca3da7b040b94a7c8b4c68dc5234556dbc1c5b51f65afc19655f6d00ab in 0.486s
PERFHERDER_DATA: {"framework": {"name": "build_metrics"}, "suites": [{"name": "fetch_content", "value": 0.4895111569785513, "lowerIsBetter": true, "shouldAlert": false, "subtests": []}]}
```

As another workaround, users could percent encode the artifact name in
the fetch config but that would result with the filename on disk still
having the percent encoded characters in it and be confusing because the
artifact in the config wouldn't match what the task actually has.

i.e: MOZ_FETCHES='[{"task":"FNpL6lwoTVyuWE3wgNeuUw","artifact":"public/Twilight%20Princess-0.2.3.apworld","extract":false}]'

Author: Eijebong

src/taskgraph/run-task/fetch-content

@@ -626,7 +626,7 @@ def fetch_and_extract(url, dest_dir, extract=True, sha256=None, size=None):
     the destination directory.
     """
 
-    basename = urllib.parse.urlparse(url).path.split("/")[-1]
+    basename = urllib.parse.unquote(urllib.parse.urlparse(url).path.split("/")[-1])
     dest_path = dest_dir / basename
 
     download_to_path(url, dest_path, sha256=sha256, size=size)
@@ -920,16 +920,17 @@ def command_task_artifacts(args):
         sha256 = None
         if fetch.get("verify-hash"):
             sha256 = get_hash(fetch, root_url)
+        encoded_artifact = urllib.parse.quote(fetch["artifact"])
         if fetch["artifact"].startswith("public/"):
             path = "task/{task}/artifacts/{artifact}".format(
-                task=fetch["task"], artifact=fetch["artifact"]
+                task=fetch["task"], artifact=encoded_artifact
             )
             url = api(root_url, "queue", "v1", path)
         else:
             url = ("{proxy_url}/api/queue/v1/task/{task}/artifacts/{artifact}").format(
                 proxy_url=os.environ["TASKCLUSTER_PROXY_URL"],
                 task=fetch["task"],
-                artifact=fetch["artifact"],
+                artifact=encoded_artifact,
             )
         downloads.append((url, extdir, fetch["extract"], sha256))
 

test/test_scripts_fetch_content.py

@@ -1,9 +1,10 @@
+import json
 import os
 import pathlib
 import urllib.request
 from importlib.machinery import SourceFileLoader
 from importlib.util import module_from_spec, spec_from_loader
-from unittest.mock import MagicMock
+from unittest.mock import MagicMock, patch
 
 import pytest
 
@@ -97,6 +98,78 @@ def getheader(field):
             raise
 
 
+@pytest.mark.parametrize(
+    "artifact,expected_url_suffix",
+    (
+        pytest.param(
+            "public/foo.apworld",
+            "task/abc123/artifacts/public/foo.apworld",
+            id="simple artifact name",
+        ),
+        pytest.param(
+            "public/Twilight Princess-0.2.3.apworld",
+            "task/abc123/artifacts/public/Twilight%20Princess-0.2.3.apworld",
+            id="artifact name with space",
+        ),
+    ),
+)
+def test_command_task_artifacts_url_encoding(
+    monkeypatch, tmp_path, fetch_content_mod,
+    artifact, expected_url_suffix,
+):
+    fetches = [{"task": "abc123", "artifact": artifact, "extract": False}]
+    monkeypatch.setenv("MOZ_FETCHES", json.dumps(fetches))
+    monkeypatch.setenv("TASKCLUSTER_ROOT_URL", "https://tc.example.com")
+
+    captured_urls = []
+
+    def mock_fetch_urls(downloads):
+        for url, dest_dir, extract, sha256 in downloads:
+            captured_urls.append(url)
+
+    monkeypatch.setattr(fetch_content_mod, "fetch_urls", mock_fetch_urls)
+
+    args = MagicMock()
+    args.dest = str(tmp_path)
+    fetch_content_mod.command_task_artifacts(args)
+
+    assert len(captured_urls) == 1
+    url = captured_urls[0]
+    assert url == f"https://tc.example.com/api/queue/v1/{expected_url_suffix}"
+
+
+@pytest.mark.parametrize(
+    "url,expected_dest_filename",
+    (
+        pytest.param(
+            "https://tc.example.com/api/queue/v1/task/abc/artifacts/public/foo.apworld",
+            "foo.apworld",
+            id="simple",
+        ),
+        pytest.param(
+            "https://tc.example.com/api/queue/v1/task/abc/artifacts/public/Twilight%20Princess-0.2.3.apworld",
+            "Twilight Princess-0.2.3.apworld",
+            id="url-encoded space",
+        ),
+    ),
+)
+def test_fetch_and_extract_dest_filename(
+    monkeypatch, tmp_path, fetch_content_mod, url, expected_dest_filename,
+):
+    downloaded_to = []
+
+    def mock_download_to_path(url, path, sha256=None, size=None):
+        downloaded_to.append(path)
+        path.touch()
+
+    monkeypatch.setattr(fetch_content_mod, "download_to_path", mock_download_to_path)
+
+    fetch_content_mod.fetch_and_extract(url, tmp_path, extract=False)
+
+    assert len(downloaded_to) == 1
+    assert downloaded_to[0].name == expected_dest_filename
+
+
 @pytest.mark.parametrize(
     "expected,orig,dest,strip_components,add_prefix",
     [