From 549f462a8ddf56d920dbad63636a5fcea53980c1 Mon Sep 17 00:00:00 2001
From: Ronny Pfannschmidt <ronny.pfannschmidt@redhat.com>
Date: Sun, 29 Nov 2020 22:32:37 +0100
Subject: [PATCH] fix #352: add a envvar to ignore scm roots

---
 CHANGELOG.rst                         |  1 +
 README.rst                            |  5 +++++
 src/setuptools_scm/file_finder.py     | 14 ++++++++++++++
 src/setuptools_scm/file_finder_git.py |  3 ++-
 src/setuptools_scm/file_finder_hg.py  |  3 ++-
 testing/test_file_finder.py           |  6 ++++++
 6 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index c376a551..34f923e9 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -1,6 +1,7 @@
 v4.2.0
 ======
 
+* fix #352: add support for generally ignoring specific vcs roots
 * fix #471: better error for version bump failing on complex but accepted tag
 * fix #479: raise indicative error when tags carry non-parsable information
 * Add `no-guess-dev` which does no next version guessing, just adds `.post1.devN` in
diff --git a/README.rst b/README.rst
index a3183327..d4b2453e 100644
--- a/README.rst
+++ b/README.rst
@@ -446,6 +446,11 @@ Environment variables
     derived, otherwise the current time is used
     (https://reproducible-builds.org/docs/source-date-epoch/)
 
+
+:SETUPTOOLS_SCM_IGNORE_VCS_ROOTS:
+    when defined, a ``os.pathsep`` separated list
+    of directory names to ignore for root finding
+
 Extending setuptools_scm
 ------------------------
 
diff --git a/src/setuptools_scm/file_finder.py b/src/setuptools_scm/file_finder.py
index 77ec1463..5b851179 100644
--- a/src/setuptools_scm/file_finder.py
+++ b/src/setuptools_scm/file_finder.py
@@ -1,4 +1,5 @@
 import os
+from .utils import trace
 
 
 def scm_find_files(path, scm_files, scm_dirs):
@@ -53,3 +54,16 @@ def _link_not_in_scm(n):
                 res.append(os.path.join(path, os.path.relpath(fullfilename, realpath)))
         seen.add(realdirpath)
     return res
+
+
+def is_toplevel_acceptable(toplevel):
+    ""
+    if toplevel is None:
+        return False
+
+    ignored = os.environ.get("SETUPTOOLS_SCM_IGNORE_VCS_ROOTS", "").split(os.pathsep)
+    ignored = [os.path.normcase(p) for p in ignored]
+
+    trace(toplevel, ignored)
+
+    return toplevel not in ignored
diff --git a/src/setuptools_scm/file_finder_git.py b/src/setuptools_scm/file_finder_git.py
index 9aa6245d..1d3e69be 100644
--- a/src/setuptools_scm/file_finder_git.py
+++ b/src/setuptools_scm/file_finder_git.py
@@ -3,6 +3,7 @@
 import tarfile
 import logging
 from .file_finder import scm_find_files
+from .file_finder import is_toplevel_acceptable
 from .utils import trace
 
 log = logging.getLogger(__name__)
@@ -60,7 +61,7 @@ def _git_ls_files_and_dirs(toplevel):
 
 def git_find_files(path=""):
     toplevel = _git_toplevel(path)
-    if not toplevel:
+    if not is_toplevel_acceptable(toplevel):
         return []
     fullpath = os.path.abspath(os.path.normpath(path))
     if not fullpath.startswith(toplevel):
diff --git a/src/setuptools_scm/file_finder_hg.py b/src/setuptools_scm/file_finder_hg.py
index 2aa1e162..816560dc 100644
--- a/src/setuptools_scm/file_finder_hg.py
+++ b/src/setuptools_scm/file_finder_hg.py
@@ -2,6 +2,7 @@
 import subprocess
 
 from .file_finder import scm_find_files
+from .file_finder import is_toplevel_acceptable
 
 
 def _hg_toplevel(path):
@@ -41,7 +42,7 @@ def _hg_ls_files_and_dirs(toplevel):
 
 def hg_find_files(path=""):
     toplevel = _hg_toplevel(path)
-    if not toplevel:
+    if not is_toplevel_acceptable(toplevel):
         return []
     hg_files, hg_dirs = _hg_ls_files_and_dirs(toplevel)
     return scm_find_files(path, hg_files, hg_dirs)
diff --git a/testing/test_file_finder.py b/testing/test_file_finder.py
index 463d3d4f..55b9cea7 100644
--- a/testing/test_file_finder.py
+++ b/testing/test_file_finder.py
@@ -126,6 +126,12 @@ def test_symlink_file_out_of_git(inwd):
     assert set(find_files("adir")) == _sep({"adir/filea"})
 
 
+@pytest.mark.parametrize("path_add", ["{cwd}", "{cwd}" + os.pathsep + "broken"])
+def test_ignore_root(inwd, monkeypatch, path_add):
+    monkeypatch.setenv("SETUPTOOLS_SCM_IGNORE_VCS_ROOTS", path_add.format(cwd=inwd.cwd))
+    assert find_files() == []
+
+
 def test_empty_root(inwd):
     subdir = inwd.cwd / "cdir" / "subdir"
     subdir.mkdir(parents=True)