fix(git): tolerate noisy git rev-parse output in is_git_project

The previous `is_git_project` implementation compared
`git rev-parse --is-inside-work-tree` output to the literal string
`"true"` after stripping. Shell wrappers that prepend ANSI colour
codes or extra whitespace (reported on git-bash + `uv tool install`
on Windows, #1497) flipped the check to `False` even when git itself
considered the directory a valid work tree.

Trust the exit code as the primary signal: if `git rev-parse` exits
non-zero, we're not in a git context. Then use a loose
`endswith("true")` match to distinguish a work tree from a bare-repo
interior. Add `logger.debug` lines so users running with `--debug`
can see exactly what git returned when the check fails.

Closes #1497

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: bearomorphism

commitizen/git.py

@@ -3,6 +3,7 @@
 import os
 from enum import Enum
 from functools import lru_cache
+from logging import getLogger
 from pathlib import Path
 from tempfile import NamedTemporaryFile
 from typing import TYPE_CHECKING
@@ -14,6 +15,9 @@
     from collections.abc import Sequence
 
 
+logger = getLogger("commitizen")
+
+
 class EOLType(Enum):
     """The EOL type from `git config core.eol`."""
 
@@ -312,8 +316,30 @@ def is_staging_clean() -> bool:
 
 
 def is_git_project() -> bool:
+    """Check whether we're inside a git work tree.
+
+    Trusts ``git rev-parse``'s exit code as the primary signal: if the command
+    exits non-zero, we're not in a git context. The textual output (``true`` /
+    ``false``) is then used to distinguish a work tree from a bare-repo
+    interior. A loose ``endswith("true")`` accepts shell wrappers that prepend
+    ANSI colour codes or trailing whitespace (#1497).
+    """
     c = cmd.run(["git", "rev-parse", "--is-inside-work-tree"])
-    return c.out.strip() == "true"
+    if c.return_code != 0:
+        logger.debug(
+            "is_git_project: git rev-parse failed (rc=%d) out=%r err=%r",
+            c.return_code,
+            c.out,
+            c.err,
+        )
+        return False
+    inside_work_tree = c.out.strip().lower().endswith("true")
+    if not inside_work_tree:
+        logger.debug(
+            "is_git_project: git rev-parse said not a work tree: out=%r",
+            c.out,
+        )
+    return inside_work_tree
 
 
 def get_core_editor() -> str | None:

tests/test_git.py

@@ -309,6 +309,37 @@ def test_is_staging_clean_when_updating_file():
     assert git.is_staging_clean() is False
 
 
+@pytest.mark.usefixtures("tmp_commitizen_project")
+def test_is_git_project_inside_work_tree():
+    assert git.is_git_project() is True
+
+
+def test_is_git_project_outside_repo(tmp_path: Path, monkeypatch: pytest.MonkeyPatch):
+    """When ``git rev-parse`` exits non-zero (no repo above us),
+    ``is_git_project`` returns ``False``."""
+    monkeypatch.chdir(tmp_path)
+    assert git.is_git_project() is False
+
+
+def test_is_git_project_accepts_loose_true_output(mocker: MockFixture):
+    """Regression test for #1497: shell wrappers that prepend ANSI colour
+    codes or trailing whitespace to ``git rev-parse``'s output must not flip
+    ``is_git_project`` to ``False``. The check now trusts the exit code and
+    a loose ``endswith('true')`` substring match."""
+    fake = cmd.Command("\x1b[0mtrue\r\n", "", b"", b"", 0)
+    mocker.patch("commitizen.cmd.run", return_value=fake)
+    assert git.is_git_project() is True
+
+
+def test_is_git_project_returns_false_for_bare_repo(mocker: MockFixture):
+    """``git rev-parse`` exits 0 but says ``false`` when run from inside the
+    ``.git`` directory of a bare repo. ``is_git_project`` is meant to gate
+    work-tree commands, so this case should still return ``False``."""
+    fake = cmd.Command("false\n", "", b"", b"", 0)
+    mocker.patch("commitizen.cmd.run", return_value=fake)
+    assert git.is_git_project() is False
+
+
 @pytest.mark.usefixtures("tmp_commitizen_project")
 def test_get_eol_for_open():
     assert git.EOLType.for_open() == os.linesep