transactions: avoid late tear-down (issue641)
We use weak references (ugh) to avoid having to manually delete
transaction references out of each call frame when an exception occurs.
adding a
diff -r 107ba6f817b5 -r 310ce7989cdc a
--- a/a Thu Jan 01 00:00:01 1970 +0000
+++ b/a Thu Jan 01 00:00:02 1970 +0000
@@ -1,2 +1,3 @@ confuse str.splitlines
confuse str.splitlines
embedded
newline
+clean diff