From f0782a6e8633988a935097c195899773da2c2ad1 Mon Sep 17 00:00:00 2001 From: Matt Stancliff Date: Fri, 7 Mar 2014 16:32:04 -0500 Subject: [PATCH] Fix key extraction for z{union,inter}store The previous implementation wasn't taking into account the storage key in position 1 being a requirement (it was only counting the source keys in positions 3 to N). Fixes antirez/redis#1581 --- src/db.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/src/db.c b/src/db.c index 41e95b6b..5170c6ed 100644 --- a/src/db.c +++ b/src/db.c @@ -993,9 +993,23 @@ int *zunionInterGetKeys(struct redisCommand *cmd,robj **argv, int argc, int *num *numkeys = 0; return NULL; } - keys = zmalloc(sizeof(int)*num); + + /* Keys in z{union,inter}store come from two places: + argv[1] = storage key, + argv[3...n] = keys to intersect */ + + /* (num+1) is (argv[2] + 1) to account for argv[1] too */ + keys = zmalloc(sizeof(int)*(num+1)); + + /* Add all key positions for argv[3...n] to keys[] */ for (i = 0; i < num; i++) keys[i] = 3+i; - *numkeys = num; + + /* Now add the argv[1] key position (the storage key target) + to our list of command positions containing keys. + num is the number of source keys, but we initialized + keys[] to size num+1, so keys[num] is safe and valid and okay. */ + keys[num] = 1; + *numkeys = num+1; /* Total keys = {union,inter} keys + storage key */ return keys; }