bpo-45401: Change shouldRollover() methods to only rollover regular f… (GH-28822) (#28867)

…iles.

Also changed some historical return values from 1 -> True and 0 -> False.
(cherry picked from commit 62a667784ba7b84611ebd50fa8a1a464cde32235)

Co-authored-by: Vinay Sajip <vinay_sajip@yahoo.co.uk>

Co-authored-by: Vinay Sajip <vinay_sajip@yahoo.co.uk>

2 files changed, 25 insertions, 4 deletions

diff --git a/Lib/logging/handlers.py b/Lib/logging/handlers.py
index 4cabc0d740..4dcbe4530f 100644
--- a/Lib/logging/handlers.py
+++ b/Lib/logging/handlers.py
@@ -187,14 +187,17 @@ class RotatingFileHandler(BaseRotatingHandler):
         Basically, see if the supplied record would cause the file to exceed
         the size limit we have.
         """
+        # See bpo-45401: Never rollover anything other than regular files
+        if os.path.exists(self.baseFilename) and not os.path.isfile(self.baseFilename):
+            return False
         if self.stream is None:                 # delay was set...
             self.stream = self._open()
         if self.maxBytes > 0:                   # are we rolling over?
             msg = "%s\n" % self.format(record)
             self.stream.seek(0, 2)  #due to non-posix-compliant Windows feature
             if self.stream.tell() + len(msg) >= self.maxBytes:
-                return 1
-        return 0
+                return True
+        return False
 
 class TimedRotatingFileHandler(BaseRotatingHandler):
     """
@@ -345,10 +348,13 @@ class TimedRotatingFileHandler(BaseRotatingHandler):
         record is not used, as we are just comparing times, but it is needed so
         the method signatures are the same
         """
+        # See bpo-45401: Never rollover anything other than regular files
+        if os.path.exists(self.baseFilename) and not os.path.isfile(self.baseFilename):
+            return False
         t = int(time.time())
         if t >= self.rolloverAt:
-            return 1
-        return 0
+            return True
+        return False
 
     def getFilesToDelete(self):
         """
diff --git a/Lib/test/test_logging.py b/Lib/test/test_logging.py
index 8356e6be24..1a5f8b60f5 100644
--- a/Lib/test/test_logging.py
+++ b/Lib/test/test_logging.py
@@ -5190,6 +5190,13 @@ class RotatingFileHandlerTest(BaseFileTest):
                 self.fn, encoding="utf-8", maxBytes=0)
         self.assertFalse(rh.shouldRollover(None))
         rh.close()
+        # bpo-45401 - test with special file
+        # We set maxBytes to 1 so that rollover would normally happen, except
+        # for the check for regular files
+        rh = logging.handlers.RotatingFileHandler(
+                os.devnull, encoding="utf-8", maxBytes=1)
+        self.assertFalse(rh.shouldRollover(self.next_rec()))
+        rh.close()
 
     def test_should_rollover(self):
         rh = logging.handlers.RotatingFileHandler(self.fn, encoding="utf-8", maxBytes=1)
@@ -5284,6 +5291,14 @@ class RotatingFileHandlerTest(BaseFileTest):
         rh.close()
 
 class TimedRotatingFileHandlerTest(BaseFileTest):
+    def test_should_not_rollover(self):
+        # See bpo-45401. Should only ever rollover regular files
+        fh = logging.handlers.TimedRotatingFileHandler(
+                os.devnull, 'S', encoding="utf-8", backupCount=1)
+        time.sleep(1.1)    # a little over a second ...
+        r = logging.makeLogRecord({'msg': 'testing - device file'})
+        self.assertFalse(fh.shouldRollover(r))
+
     # other test methods added below
     def test_rollover(self):
         fh = logging.handlers.TimedRotatingFileHandler(