[PATCH] checksum: fix unstable sort of checksums

[<yang.xu@mediatek.com>]

From: Yang Xu <yang.xu@mediatek.com>

Using only the checksum as sorting key can lead to unstable results when
same content files exist in different subfolders, affecting the taskhash
calculation due to its sensitivity to the order of files in checksums.

This commit changes the sorting key to use both checksum and file path,
ensuring stable sorting and enhancing sstate cache hit rates.

Signed-off-by: Yang Xu <yang.xu@mediatek.com>
---
 lib/bb/checksum.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/bb/checksum.py b/lib/bb/checksum.py
index 557793d3..5294ddf1 100644
--- a/lib/bb/checksum.py
+++ b/lib/bb/checksum.py
@@ -140,5 +140,5 @@ class FileChecksumCache(MultiProcessCache):
                 if checksum:
                     checksums.append((pth, checksum))
 
-        checksums.sort(key=operator.itemgetter(1))
+        checksums.sort(key=lambda x:(x[1], x[0]))
         return checksums
-- 
2.25.1