From 18639c7b5fa26899c7a9beee02de860e1d528709 Mon Sep 17 00:00:00 2001
From: DWesl <22566757+DWesl@users.noreply.github.com>
Date: Wed, 5 Nov 2025 14:24:46 -0500
Subject: [PATCH] Change FileStream to use absolute paths

Currently, accessing a grib file first by a relative path then by an absolute path causes cfgrib to reject the index, as would acessing the file by a relative path from a different working directory.

This change ensures the path stored in the index file is absolute, so the index file validator will find a match regardless of whether the file is accessed by a relative path or an absolute path.
---
 cfgrib/messages.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/cfgrib/messages.py b/cfgrib/messages.py
index 17a4e752..b68d991a 100644
--- a/cfgrib/messages.py
+++ b/cfgrib/messages.py
@@ -322,7 +322,9 @@ class FileStream(abc.MappingFieldset[OffsetType, Message]):
     14760.0
     """
 
-    path: str
+    path: str = attr.field(
+        converter=os.path.abspath, eq=os.path.abspath, on_setattr=os.path.abspath
+    )
     errors: str = attr.attrib(
         default="warn", validator=attr.validators.in_(["ignore", "warn", "raise"])
     )