Comment fix.

diff --git a/src/include/access/gist.h b/src/include/access/gist.h
index 9f4e2de0788b9a2b69686b29b44b853f898fc401..57911783160202f36060bb298cc1ce0a54cb4afe 100644 (file)
--- a/src/include/access/gist.h
+++ b/src/include/access/gist.h
@@ -141,8 +141,9 @@ typedef struct GISTENTRY
 /*
  * Prior to PostgreSQL 9.3, the F_ROOT flag did not exist; the root page was
  * at a fixed location, GIST_OLD_ROOT_BLKNO.  This block now contains the
- * metapage.  The correct test for whether you've got the root block is
- * therefore blkno == 0 || GistPageIsRoot(page).
+ * metapage.  To accommodate pg_upgrade from earlier server versions, the
+ * correct test for whether you've got the root block is therefore blkno == 0
+ * || GistPageIsRoot(page).
  */
 #define GistPageIsRoot(page)   ( GistPageGetOpaque(page)->flags & F_ROOT)