(Risk 2) Keep phantom hotfix hfrev/version fresh in update_versions

Phantom hotfixes (stored in _phantom_hotfixes for non-hotfix PR cascades)
were never iterated by update_versions(), leaving their .hfrev and
.version frozen at the initial pre-GA values forever.  Today only
.minor is consumed (_update_major_versions), so there is no live bug,
but any future caller reading .hfrev or .version would silently get
stale data.

Apply the same hfrev advancement logic to phantom hotfixes inside
update_versions() so their state stays consistent with the cascade.

Add a QuickTest that builds a cascade with a phantom hotfix, processes
a GA tag, and asserts hfrev advances to 1.  The test fails without the
fix because the phantom is never updated.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: charlesprost

bert_e/tests/test_bert_e.py

@@ -540,6 +540,33 @@ def test_branch_cascade_2digit_with_pre_ga_hotfix(self):
         fixver = ['9.5.3', '10.0.1', '10.1.0']
         self.finalize_cascade(branches, tags, destination, fixver)
 
+    def test_phantom_hotfix_hfrev_updated_by_ga_tag(self):
+        """Phantom hotfix hfrev and version must be updated by update_versions.
+
+        When hotfix/10.0.0 is stored as a phantom (non-hotfix PR destination),
+        update_versions() must still advance its hfrev when GA tags arrive.
+        Without the fix the phantom's hfrev stays at 0 forever, exposing
+        stale data to any future caller that reads .hfrev or .version.
+        """
+        my_dst = gwfb.branch_factory(FakeGitRepo(), 'development/10')
+        cascade = gwfb.BranchCascade()
+        for name in ('development/9.5', 'hotfix/10.0.0', 'development/10'):
+            cascade.add_branch(gwfb.branch_factory(FakeGitRepo(), name),
+                               my_dst)
+
+        self.assertEqual(len(cascade._phantom_hotfixes), 1)
+        phantom = cascade._phantom_hotfixes[0]
+
+        # Pre-GA: no 10.0.0.X tags — hfrev must remain 0
+        cascade.update_versions('9.5.2')
+        self.assertEqual(phantom.hfrev, 0)
+        self.assertEqual(phantom.version, '10.0.0.0')
+
+        # GA tag 10.0.0.0 lands — phantom hfrev must advance to 1
+        cascade.update_versions('10.0.0.0')
+        self.assertEqual(phantom.hfrev, 1)        # fails without the fix
+        self.assertEqual(phantom.version, '10.0.0.1')
+
     def test_branch_cascade_target_three_digit_dev(self):
         """Test cascade targeting three-digit development branch"""
         destination = 'development/4.3.17'

bert_e/workflow/gitwaterflow/branches.py

@@ -1018,6 +1018,17 @@ def update_versions(self, tag):
                                                      hf_branch.micro,
                                                      hf_branch.hfrev)
 
+        # Also update phantom hotfixes (stored outside _cascade for dev PRs).
+        # They are only consumed for their .minor today, but keeping .hfrev
+        # and .version current prevents stale data surprises in future callers.
+        for phantom in self._phantom_hotfixes:
+            if (phantom.major == major and phantom.minor == minor and
+                    phantom.micro == micro):
+                phantom.hfrev = max(hfrev + 1, phantom.hfrev)
+                phantom.version = '%d.%d.%d.%d' % (
+                    phantom.major, phantom.minor,
+                    phantom.micro, phantom.hfrev)
+
         if micro_branch is not None and \
            ([micro_branch.major, micro_branch.minor,
              micro_branch.micro] == [major, minor, micro]):