fix: reject checkout shorthand when creating branches (#4843)

* fix: reject branch shorthand during validation

* test: add regression coverage for branch-ref validation

Cover github_create_branch: rejects checkout shorthand (@{-1}) via literal
refs/heads/<name> validation, accepts ordinary slash names, and never uses
--branch (which would expand shorthand before checkout -B).

Co-authored-by: Mervin Praison <[email protected]>

* fix: clear rejected branch from sticky comment

* fix: preserve sticky branch after rejected creation

---------

Co-authored-by: praisonai-triage-agent[bot] <272766704+praisonai-triage-agent[bot]@users.noreply.github.com>
Co-authored-by: Mervin Praison <[email protected]>

src/praisonai-agents/praisonaiagents/tools/github_tools.py

@@ -136,7 +136,7 @@ def github_create_branch(branch_name: str) -> str:
         # Validate branch name to prevent misinterpretation as git options or invalid refs
         try:
             subprocess.run(
-                ["git", "check-ref-format", "--branch", branch_name],
+                ["git", "check-ref-format", f"refs/heads/{branch_name}"],
                 check=True, capture_output=True, text=True
             )
         except subprocess.CalledProcessError as e:

src/praisonai-agents/tests/integration/test_github_enhanced_comment.py

@@ -255,6 +255,53 @@ class TestEnhancedStickyComment:
         # File should be clickable link
         assert "https://github.com/MervinPraison/PraisonAI/blob/feature/test/src/main.py" in body
 
+    def test_failed_branch_creation_clears_sticky_branch(self):
+        """A rejected branch must not remain rendered as active."""
+        from praisonai.cli.commands.github import StickyComment
+
+        sticky = StickyComment(
+            api_base="https://api.github.com",
+            issue=112,
+            token="fake",
+            task_type="Issue",
+            title="Test",
+            run_url="",
+            repo_name="owner/repo",
+        )
+
+        sticky.set_branch("@{-1}")
+        sticky.on_tool_end("agent", "github_create_branch", "Error: invalid branch name '@{-1}'")
+
+        assert sticky._branch_name is None
+        assert "@{-1}" not in sticky._build_body()
+
+    def test_failed_branch_creation_restores_prior_sticky_branch_and_refreshes(self, monkeypatch):
+        """A failed later creation restores the displayed active branch."""
+        from praisonai.cli.commands.github import StickyComment
+
+        sticky = StickyComment(
+            api_base="https://api.github.com",
+            issue=113,
+            token="fake",
+            task_type="Issue",
+            title="Test",
+            run_url="",
+            repo_name="owner/repo",
+        )
+        sticky.set_branch("feature/active")
+        sticky.on_tool_start("agent", "github_create_branch", {"branch_name": "@{-1}"})
+        sticky.set_branch("@{-1}")
+        refreshes = []
+        monkeypatch.setattr(sticky, "_schedule_push", lambda: refreshes.append(True))
+
+        sticky.on_tool_end("agent", "github_create_branch", "Error: invalid branch name '@{-1}'")
+
+        assert sticky._branch_name == "feature/active"
+        body = sticky._build_body()
+        assert "[🌿 `feature/active`]" in body
+        assert "[🌿 `@{-1}`]" not in body
+        assert refreshes == [True]
+
 
 @pytest.mark.manual
 class TestEnhancedIntegration:

src/praisonai-agents/tests/unit/tools/test_github_branch_safety.py

@@ -215,3 +215,44 @@ def test_slugify_and_auto_branch():
     name = github_tools._auto_branch_name("Fix parser")
     assert name.startswith("praisonai/fix-parser-")
     assert github_tools._branch_push_safety("praisonai/anything") is None
+
+
+def test_create_branch_validates_full_ref(monkeypatch):
+    # Validation must check the literal ``refs/heads/<name>`` ref so Git cannot
+    # expand checkout shorthand (e.g. ``@{-1}``) before ``checkout -B`` runs.
+    responses = {
+        ("rev-parse", "--is-inside-work-tree"): ("true\n", 0),
+    }
+    calls = _call(monkeypatch, responses)
+    _run_tool(github_tools.github_create_branch, "praisonai/fix")
+    ref_checks = [c for c in calls if c[:2] == ["git", "check-ref-format"]]
+    assert ref_checks, "expected a check-ref-format validation"
+    for c in ref_checks:
+        assert "--branch" not in c, "must not use --branch (expands shorthand)"
+        assert "refs/heads/praisonai/fix" in c
+
+
+def test_create_branch_rejects_checkout_shorthand(monkeypatch):
+    # ``@{-1}`` is a valid checkout shorthand but an invalid full ref, so it must
+    # be rejected before any checkout runs (no destructive branch reset).
+    responses = {
+        ("rev-parse", "--is-inside-work-tree"): ("true\n", 0),
+        ("check-ref-format", "refs/heads/@{-1}"): ("", 1),
+    }
+    calls = _call(monkeypatch, responses)
+    result = _run_tool(github_tools.github_create_branch, "@{-1}")
+    assert "invalid branch name" in result
+    assert not [c for c in calls if c[:2] == ["git", "checkout"]]
+
+
+def test_create_branch_accepts_slash_names(monkeypatch):
+    # Ordinary slash-containing branch names must still be created.
+    responses = {
+        ("rev-parse", "--is-inside-work-tree"): ("true\n", 0),
+    }
+    calls = _call(monkeypatch, responses)
+    result = _run_tool(github_tools.github_create_branch, "feature/new-thing")
+    assert "Successfully" in result
+    checkouts = [c for c in calls if c[:2] == ["git", "checkout"]]
+    assert checkouts, "expected a checkout for a valid branch name"
+    assert ["git", "checkout", "-B", "feature/new-thing"] in checkouts

src/praisonai-code/praisonai_code/cli/commands/github.py

@@ -73,6 +73,7 @@ class StickyComment:
 
         # Branch and PR tracking
         self._branch_name: Optional[str] = None
+        self._branch_before_create: Optional[str] = None
         self._pr_url: Optional[str] = None
         self._pr_number: Optional[int] = None
         self._summary_lines: List[str] = []
@@ -161,6 +162,8 @@ class StickyComment:
     def on_tool_start(self, agent_name: str, tool_name: str, tool_args: dict) -> None:
         with self._lock:
             self._current_tool = tool_name
+            if tool_name == "github_create_branch":
+                self._branch_before_create = self._branch_name
             label = self._tool_label(tool_name, tool_args)
             self._logs.append(f"🔧 {label}")
             # Extract file modifications from commands
@@ -169,12 +172,23 @@ class StickyComment:
         self._schedule_push()
 
     def on_tool_end(self, agent_name: str, tool_name: str, result: Any = None) -> None:
+        refresh = False
         with self._lock:
             self._current_tool = None
+            # A branch name is captured eagerly at tool start so the live
+            # comment can show the operation immediately.  Do not leave a
+            # rejected branch rendered as active after validation or checkout
+            # fails.
+            if tool_name == "github_create_branch" and str(result).startswith("Error"):
+                self._branch_name = self._branch_before_create
+                refresh = True
+            if tool_name == "github_create_branch":
+                self._branch_before_create = None
             # Extract features from tool results
             if result and isinstance(result, str):
                 self._extract_features_from_output(result)
-        # no extra log for tool end – keeps comment clean
+        if refresh:
+            self._schedule_push()
 
     def _extract_file_from_command(self, command: str) -> None:
         """Extract file paths from shell commands to track modifications."""