Merge pull request #805 from omacom/fix/redirect-watch-probe

upstream-watch: probe redirect watches past a staged rollout

helpers/upstream-watch.py

@@ -26,6 +26,8 @@ VERSION = re.compile(r"[A-Za-z0-9][A-Za-z0-9._+]*\Z")
 SCALAR = re.compile(r"[A-Za-z0-9._+/-]+\Z")
 SUM = re.compile(r"(md5|sha1|sha224|sha256|sha384|sha512|b2)sums(_[a-z0-9_]+)?\Z")
 HASHES = {"b2": "blake2b"}
+# How many times a redirect watch probes before it calls the feed unmatched.
+REDIRECT_PROBES = 5
 
 
 def run(args, **kwargs):
@@ -286,8 +288,16 @@ def discover(watch, fetch):
         values.update({name: json_path(data, path) for name, path in watch.get("fields", {}).items()})
         results.append(candidate(watch, values))
     elif provider == "redirect":
-        final_url = run(["curl", "--proto", "=https", "--proto-redir", "=https", "-fsSLI", "--max-time", "60", "-o", "/dev/null", "-w", "%{url_effective}", feed], text=True)
-        results.extend(matches(watch, final_url))
+        # A download redirect can be a staged rollout: some requests land on a
+        # newer build the pattern deliberately rejects (Dropbox, 2026-10-04:
+        # 4 of 100 HEADs ended at 274.3.4801 instead of 272.4.3798), so one
+        # probe that misses is not an answer. Keep the first one that matches.
+        for _ in range(REDIRECT_PROBES):
+            final_url = run(["curl", "--proto", "=https", "--proto-redir", "=https", "-fsSLI", "--max-time", "60", "--retry", "2",
+                             "-o", "/dev/null", "-w", "%{url_effective}", feed], text=True)
+            results.extend(matches(watch, final_url))
+            if results:
+                break
     elif provider == "regex":
         text = fetch.text(feed)
         if watch.get("unescape_json"):

tests/upstream-watch.py

@@ -160,6 +160,24 @@ b2sums=('old' 'local-b2')
         output = w.replace_array(text, 'sha256sums', ['abc'])
         self.assertEqual(output, "sha256sums=('abc') # trailing\npackage() { :; }\n")
 
+    def test_redirect_probes_past_a_staged_rollout(self):
+        watch = {"redirect": "https://example.test/download",
+                 "pattern": r"tool-(?P<version>[0-9]+\.4\.[0-9]+)\.tar\.gz"}
+        rollout = "https://cdn.example.test/tool-274.3.4801.tar.gz"
+        stable = "https://cdn.example.test/tool-272.4.3798.tar.gz"
+        with patch.object(w, 'run', side_effect=[rollout, rollout, stable]) as probe:
+            releases = w.discover(watch, self.fetch)
+        self.assertEqual([r["pkgver"] for r in releases], ["272.4.3798"])
+        self.assertEqual(probe.call_count, 3)
+
+    def test_redirect_gives_up_after_its_probes(self):
+        watch = {"redirect": "https://example.test/download",
+                 "pattern": r"tool-(?P<version>[0-9]+\.4\.[0-9]+)\.tar\.gz"}
+        with patch.object(w, 'run', return_value="https://cdn.example.test/tool-274.3.4801.tar.gz") as probe, \
+                self.assertRaisesRegex(ValueError, 'no matching releases'):
+            w.discover(watch, self.fetch)
+        self.assertEqual(probe.call_count, w.REDIRECT_PROBES)
+
     def test_git_hash_matches_makepkg(self):
         repo = self.root / 'git'
         repo.mkdir()