SERVER-23040: Coverity analysis defect 98151: Dereference after null check

We always truncate in cursor-forward direction, there's never a case
where we don't have a "start" cursor. Simplify some code and stop
checking if the start cursor is set or not.

2 files changed, 6 insertions, 17 deletions

diff --git a/src/btree/bt_cursor.c b/src/btree/bt_cursor.c
index c11b7d35de6..d64b6064268 100644
--- a/src/btree/bt_cursor.c
+++ b/src/btree/bt_cursor.c
@@ -1162,22 +1162,14 @@ int
 __wt_btcur_range_truncate(WT_CURSOR_BTREE *start, WT_CURSOR_BTREE *stop)
 {
 	WT_BTREE *btree;
-	WT_CURSOR_BTREE *cbt;
 	WT_DECL_RET;
 	WT_SESSION_IMPL *session;
 
-	cbt = (start != NULL) ? start : stop;
-	session = (WT_SESSION_IMPL *)cbt->iface.session;
-	btree = cbt->btree;
+	session = (WT_SESSION_IMPL *)start->iface.session;
+	btree = start->btree;
 	WT_STAT_FAST_DATA_INCR(session, cursor_truncate);
 
 	/*
-	 * We always delete in a forward direction because it's faster, assert
-	 * our caller provided us with a start cursor.
-	 */
-	WT_ASSERT(session, start != NULL);
-
-	/*
 	 * For recovery, log the start and stop keys for a truncate operation,
 	 * not the individual records removed.  On the other hand, for rollback
 	 * we need to keep track of all the in-memory operations.
diff --git a/src/schema/schema_truncate.c b/src/schema/schema_truncate.c
index e7752b60ca4..d9a798b6ed8 100644
--- a/src/schema/schema_truncate.c
+++ b/src/schema/schema_truncate.c
@@ -131,22 +131,19 @@ int
 __wt_schema_range_truncate(
     WT_SESSION_IMPL *session, WT_CURSOR *start, WT_CURSOR *stop)
 {
-	WT_CURSOR *cursor;
 	WT_DATA_SOURCE *dsrc;
 	WT_DECL_RET;
 	const char *uri;
 
-	cursor = (start != NULL) ? start : stop;
-	uri = cursor->internal_uri;
+	uri = start->internal_uri;
 
 	if (WT_PREFIX_MATCH(uri, "file:")) {
-		if (start != NULL)
-			WT_CURSOR_NEEDKEY(start);
+		WT_CURSOR_NEEDKEY(start);
 		if (stop != NULL)
 			WT_CURSOR_NEEDKEY(stop);
-		WT_WITH_BTREE(session, ((WT_CURSOR_BTREE *)cursor)->btree,
+		WT_WITH_BTREE(session, ((WT_CURSOR_BTREE *)start)->btree,
 		    ret = __wt_btcur_range_truncate(
-			(WT_CURSOR_BTREE *)start, (WT_CURSOR_BTREE *)stop));
+		    (WT_CURSOR_BTREE *)start, (WT_CURSOR_BTREE *)stop));
 	} else if (WT_PREFIX_MATCH(uri, "table:"))
 		ret = __wt_table_range_truncate(
 		    (WT_CURSOR_TABLE *)start, (WT_CURSOR_TABLE *)stop);