fix locate_file (#5606)

* fix

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* fix

---------

Co-authored-by: a <1@1.1>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

news/fix_locate_file.rst

@@ -0,0 +1,23 @@
+**Added:**
+
+* <news item>
+
+**Changed:**
+
+* <news item>
+
+**Deprecated:**
+
+* <news item>
+
+**Removed:**
+
+* <news item>
+
+**Fixed:**
+
+* Fixed wrong order of directories in PATH (#5606 #5605). Please do not use 0.18.0 and 0.18.1 versions.
+
+**Security:**
+
+* <news item>

tests/procs/test_executables.py

@@ -24,18 +24,26 @@ def test_get_paths(tmpdir):
 
 
 def test_locate_executable(tmpdir, xession):
-    bindir = tmpdir.mkdir("bindir")
-    bindir.mkdir("subdir")
+    bindir1 = tmpdir.mkdir("bindir1")
+    bindir2 = tmpdir.mkdir("bindir2")
+    bindir3 = tmpdir.mkdir("bindir3")
+    bindir2.mkdir("subdir")
     executables = ["file1.EXE", "file2.COM", "file2.EXE", "file3"]
     not_executables = ["file4.EXE", "file5"]
     for exefile in executables + not_executables:
-        f = bindir / exefile
+        f = bindir2 / exefile
         f.write_text("binary", encoding="utf8")
         if exefile in executables:
             os.chmod(f, 0o777)
 
+    # Test overlapping file names in different bin directories.
+    (f := bindir3 / "file3").write_text("binary", encoding="utf8")
+    os.chmod(f, 0o777)
+
     pathext = [".EXE", ".COM"] if ON_WINDOWS else []
-    with xession.env.swap(PATH=str(bindir), PATHEXT=pathext):
+    with xession.env.swap(
+        PATH=[str(bindir1), str(bindir2), str(bindir3)], PATHEXT=pathext
+    ):
         assert locate_executable("file1.EXE")
         assert locate_executable("nofile") is None
         assert locate_executable("file5") is None
@@ -45,7 +53,7 @@ def test_locate_executable(tmpdir, xession):
             assert locate_executable("file4")
             assert locate_executable("file2").endswith("file2.exe")
         else:
-            assert locate_executable("file3")
+            assert locate_executable("file3").find("bindir2") > 0
             assert locate_executable("file1") is None
             assert locate_executable("file4") is None
             assert locate_executable("file2") is None

xonsh/procs/executables.py

@@ -89,7 +89,7 @@ def locate_file(name, env=None, check_executable=False, use_pathext=False):
     """
     env = env if env is not None else XSH.env
     env_path = env.get("PATH", [])
-    paths = tuple(reversed(tuple(clear_paths(env_path))))
+    paths = tuple(tuple(clear_paths(env_path)))
     possible_names = get_possible_names(name, env) if use_pathext else [name]
 
     for path, possible_name in itertools.product(paths, possible_names):