diff -r b9a355763e76 -r a41eeb877d07 mercurial/revlog.py
--- a/mercurial/revlog.py	Tue Jun 20 02:36:52 2023 +0200
+++ b/mercurial/revlog.py	Sun Jun 18 00:09:39 2023 +0200
@@ -615,8 +615,8 @@
             entry_point = b'%s.i.%s' % (self.radix, self.postfix)
         elif self._trypending and self.opener.exists(b'%s.i.a' % self.radix):
             entry_point = b'%s.i.a' % self.radix
-        elif self._try_split and self.opener.exists(b'%s.i.s' % self.radix):
-            entry_point = b'%s.i.s' % self.radix
+        elif self._try_split and self.opener.exists(self._split_index_file):
+            entry_point = self._split_index_file
         else:
             entry_point = b'%s.i' % self.radix
 
@@ -2125,6 +2125,22 @@
                 raise error.CensoredNodeError(self.display_id, node, text)
             raise
 
+    @property
+    def _split_index_file(self):
+        """the path where to expect the index of an ongoing splitting operation
+
+        The file will only exist if a splitting operation is in progress, but
+        it is always expected at the same location."""
+        parts = os.path.split(self.radix)
+        if len(parts) > 1:
+            # adds a '-s' prefix to the ``data/` or `meta/` base
+            head = parts[0] + b'-s'
+            return os.path.join(head, *parts[1:])
+        else:
+            # the revlog is stored at the root of the store (changelog or
+            # manifest), no risk of collision.
+            return self.radix + b'.i.s'
+
     def _enforceinlinesize(self, tr, side_write=True):
         """Check if the revlog is too big for inline and convert if so.
 
@@ -2161,7 +2177,7 @@
             # this code
         if side_write:
             old_index_file_path = self._indexfile
-            new_index_file_path = self._indexfile + b'.s'
+            new_index_file_path = self._split_index_file
             opener = self.opener
             weak_self = weakref.ref(self)