Restore accidentally-removed line.

robertmhaas · robertmhaas · commit 814573e6c488 · 2017-05-31T14:24:22.000-04:00
Commit 88e66d1 is to blame. Masahiko Sawada Discussion: http://postgr.es/m/CAD21AoAXeb7O4hgg+efs8JT_SxpR4doAH5c5s-Z5WoRLstBZJA@mail.gmail.com
diff --git a/src/backend/access/transam/subtrans.c b/src/backend/access/transam/subtrans.c
@@ -10,6 +10,7 @@
  * The tree can easily be walked from child to parent, but not in the
  * opposite direction.
  *
+ * This code is based on xact.c, but the robustness requirements
  * are completely different from pg_xact, because we only need to remember
  * pg_subtrans information for currently-open transactions.  Thus, there is
  * no need to preserve data over a crash and restart.

Original file line number	Diff line number	Diff line change
`@@ -10,6 +10,7 @@`
`10`	`10`	`* The tree can easily be walked from child to parent, but not in the`
`11`	`11`	`* opposite direction.`
`12`	`12`	`*`
	`13`	`+ * This code is based on xact.c, but the robustness requirements`
`13`	`14`	`* are completely different from pg_xact, because we only need to remember`
`14`	`15`	`* pg_subtrans information for currently-open transactions. Thus, there is`
`15`	`16`	`* no need to preserve data over a crash and restart.`