output: relative paths outside of repo (#5893)

* output: relative paths outside of repo

Fixes #5870

* scm: enhance FileNotInRepo message

dvc/output/local.py

@@ -48,7 +48,11 @@ class LocalOutput(BaseOutput):
         return self.FS_CLS.PATH_CLS(abs_p)
 
     def __str__(self):
-        if not self.repo or not self.is_in_repo:
+        if (
+            not self.repo
+            or urlparse(self.def_path).scheme == "remote"
+            or os.path.isabs(self.def_path)
+        ):
             return str(self.def_path)
 
         cur_dir = os.getcwd()
@@ -63,8 +67,15 @@ class LocalOutput(BaseOutput):
 
     @property
     def is_in_repo(self):
-        def_scheme = urlparse(self.def_path).scheme
-        return def_scheme != "remote" and not os.path.isabs(self.def_path)
+        if urlparse(self.def_path).scheme == "remote":
+            return False
+
+        if os.path.isabs(self.def_path):
+            return False
+
+        if self.repo and not self.path_info.isin(self.repo.root_dir):
+            return False
+        return True
 
     def dumpd(self):
         ret = super().dumpd()

dvc/scm/git/__init__.py

@@ -151,7 +151,9 @@ class Git(Base):
         gitignore = os.path.join(ignore_file_dir, self.GITIGNORE)
 
         if not path_isin(os.path.realpath(gitignore), self.root_dir):
-            raise FileNotInRepoError(path)
+            raise FileNotInRepoError(
+                f"'{path}' is outside of git repository '{self.root_dir}'"
+            )
 
         return entry, gitignore
 

tests/func/test_add.py

@@ -347,6 +347,24 @@ def test_add_external_file(tmp_dir, dvc, workspace, hash_name, hash_value):
     assert dvc.status() == {}
 
 
+def test_add_external_relpath(tmp_dir, dvc, local_cloud):
+    (fpath,) = local_cloud.gen("file", "file")
+    rel = os.path.relpath(fpath)
+
+    with pytest.raises(StageExternalOutputsError):
+        dvc.add(rel)
+
+    dvc.add(rel, external=True)
+    assert (tmp_dir / "file.dvc").read_text() == (
+        "outs:\n"
+        "- md5: 8c7dd922ad47494fc02c388e12c00eac\n"
+        "  size: 4\n"
+        f"  path: {rel}\n"
+    )
+    assert fpath.read_text() == "file"
+    assert dvc.status() == {}
+
+
 @pytest.mark.parametrize(
     "workspace, hash_name, hash_value",
     [