fix ZRANK (realize that rank is 1-based due to the skip list header)

diff --git a/redis.c b/redis.c
index 8f524dd62b17ceeba7e3467b02a4cd403b1fc25d..6ad439b0c73fa179f227bdef1f6e05cb83f067c5 100644 (file)
--- a/redis.c
+++ b/redis.c
@@ -5483,13 +5483,16 @@ static void zrankCommand(redisClient *c) {
         while (x->forward[i] &&
             (x->forward[i]->score < *score ||
                 (x->forward[i]->score == *score &&
-                compareStringObjects(x->forward[i]->obj,c->argv[2]) < 0))) {
+                compareStringObjects(x->forward[i]->obj,c->argv[2]) <= 0))) {
             rank += x->span[i];
             x = x->forward[i];
         }
 
-        if (x->forward[i] && compareStringObjects(x->forward[i]->obj,c->argv[2]) == 0) {
-            addReplyLong(c, rank);
+        /* x might be equal to zsl->header, so test if obj is non-NULL */
+        if (x->obj && compareStringObjects(x->obj,c->argv[2]) == 0) {
+            /* the pointer from zsl->header to the first element also spans one,
+             * which makes the rank 1-based */
+            addReplyLong(c, rank-1);
             return;
         }
     }

diff --git a/test-redis.tcl b/test-redis.tcl
index 4ec3830eebbea8390b6c9897b0c662c97789140a..0fc1e7dfc9b871447e125803c8fb07503ac8d79c 100644 (file)
--- a/test-redis.tcl
+++ b/test-redis.tcl
@@ -1545,7 +1545,7 @@ proc main {server port} {
                 set ele [lindex [$r zrange myzset $index $index] 0]
                 set rank [$r zrank myzset $ele]
                 if {$rank != $index} {
-                    set err "$ele RANK is wrong! ($rank != [expr $index+1])"
+                    set err "$ele RANK is wrong! ($rank != $index)"
                     break
                 }
             }