From 99a73c3465a45fe57cac01a917fc50e0743b5964 Mon Sep 17 00:00:00 2001
From: Jacob Walls <jacobtylerwalls@gmail.com>
Date: Mon, 27 Nov 2023 13:05:55 -0500
Subject: [PATCH] gh-76912: Raise OSError from any failure in getpass.getuser()
 (#29739)

* bpo-32731: Raise OSError from any failure in getpass.getuser()
Previously, if the username was not set in certain environment variables, ImportError escaped on Windows systems, and it was possible for KeyError to escape on other systems if getpwuid() failed.
---
 Doc/library/getpass.rst                             |  7 +++++--
 Doc/whatsnew/3.13.rst                               |  4 ++++
 Lib/getpass.py                                      | 13 ++++++++++---
 Lib/test/test_getpass.py                            |  4 ++--
 .../2021-11-23-22-22-49.bpo-32731.kNOASr.rst        |  3 +++
 5 files changed, 24 insertions(+), 7 deletions(-)
 create mode 100644 Misc/NEWS.d/next/Library/2021-11-23-22-22-49.bpo-32731.kNOASr.rst

diff --git a/Doc/library/getpass.rst b/Doc/library/getpass.rst
index 5c79daf0f47..54c84d45a59 100644
--- a/Doc/library/getpass.rst
+++ b/Doc/library/getpass.rst
@@ -46,7 +46,10 @@ The :mod:`getpass` module provides two functions:
    :envvar:`USER`, :envvar:`!LNAME` and :envvar:`USERNAME`, in order, and
    returns the value of the first one which is set to a non-empty string.  If
    none are set, the login name from the password database is returned on
-   systems which support the :mod:`pwd` module, otherwise, an exception is
-   raised.
+   systems which support the :mod:`pwd` module, otherwise, an :exc:`OSError`
+   is raised.
 
    In general, this function should be preferred over :func:`os.getlogin()`.
+
+   .. versionchanged:: 3.13
+      Previously, various exceptions beyond just :exc:`OSError` were raised.
diff --git a/Doc/whatsnew/3.13.rst b/Doc/whatsnew/3.13.rst
index 3fd0f5e165f..ec09dfea4aa 100644
--- a/Doc/whatsnew/3.13.rst
+++ b/Doc/whatsnew/3.13.rst
@@ -1032,6 +1032,10 @@ Changes in the Python API
   recomended in the documentation.
   (Contributed by Serhiy Storchaka in :gh:`106672`.)
 
+* An :exc:`OSError` is now raised by :func:`getpass.getuser` for any failure to
+  retrieve a username, instead of :exc:`ImportError` on non-Unix platforms or
+  :exc:`KeyError` on Unix platforms where the password database is empty.
+
 
 Build Changes
 =============
diff --git a/Lib/getpass.py b/Lib/getpass.py
index 8b42c0a536b..bd0097ced94 100644
--- a/Lib/getpass.py
+++ b/Lib/getpass.py
@@ -156,7 +156,11 @@ def getuser():
 
     First try various environment variables, then the password
     database.  This works on Windows as long as USERNAME is set.
+    Any failure to find a username raises OSError.
 
+    .. versionchanged:: 3.13
+        Previously, various exceptions beyond just :exc:`OSError`
+        were raised.
     """
 
     for name in ('LOGNAME', 'USER', 'LNAME', 'USERNAME'):
@@ -164,9 +168,12 @@ def getuser():
         if user:
             return user
 
-    # If this fails, the exception will "explain" why
-    import pwd
-    return pwd.getpwuid(os.getuid())[0]
+    try:
+        import pwd
+        return pwd.getpwuid(os.getuid())[0]
+    except (ImportError, KeyError) as e:
+        raise OSError('No username set in the environment') from e
+
 
 # Bind the name getpass to the appropriate function
 try:
diff --git a/Lib/test/test_getpass.py b/Lib/test/test_getpass.py
index 98ecec94336..80dda2caaa3 100644
--- a/Lib/test/test_getpass.py
+++ b/Lib/test/test_getpass.py
@@ -26,7 +26,7 @@ class GetpassGetuserTest(unittest.TestCase):
         environ.get.return_value = None
         try:
             getpass.getuser()
-        except ImportError: # in case there's no pwd module
+        except OSError:  # in case there's no pwd module
             pass
         except KeyError:
             # current user has no pwd entry
@@ -47,7 +47,7 @@ class GetpassGetuserTest(unittest.TestCase):
                                  getpass.getuser())
                 getpw.assert_called_once_with(42)
         else:
-            self.assertRaises(ImportError, getpass.getuser)
+            self.assertRaises(OSError, getpass.getuser)
 
 
 class GetpassRawinputTest(unittest.TestCase):
diff --git a/Misc/NEWS.d/next/Library/2021-11-23-22-22-49.bpo-32731.kNOASr.rst b/Misc/NEWS.d/next/Library/2021-11-23-22-22-49.bpo-32731.kNOASr.rst
new file mode 100644
index 00000000000..92f3b870c11
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2021-11-23-22-22-49.bpo-32731.kNOASr.rst
@@ -0,0 +1,3 @@
+:func:`getpass.getuser` now raises :exc:`OSError` for all failures rather
+than :exc:`ImportError` on systems lacking the :mod:`pwd` module or
+:exc:`KeyError` if the password database is empty.