merged code from 184d74ab, 4774a53b, f483ce5f to new file structure

src/t_list.c

@@ -476,11 +476,10 @@ void lrangeCommand(redisClient *c) {
     if (start < 0) start = llen+start;
     if (end < 0) end = llen+end;
     if (start < 0) start = 0;
-    if (end < 0) end = 0;
 
-    /* indexes sanity checks */
+    /* Invariant: start >= 0, so this test will be true when end < 0.
+     * The range is empty when start > end or start >= length. */
     if (start > end || start >= llen) {
-        /* Out of range start or start > end result in empty list */
         addReply(c,shared.emptymultibulk);
         return;
     }
@@ -516,9 +515,9 @@ void ltrimCommand(redisClient *c) {
     if (start < 0) start = llen+start;
     if (end < 0) end = llen+end;
     if (start < 0) start = 0;
-    if (end < 0) end = 0;
 
-    /* indexes sanity checks */
+    /* Invariant: start >= 0, so this test will be true when end < 0.
+     * The range is empty when start > end or start >= length. */
     if (start > end || start >= llen) {
         /* Out of range start or start > end result in empty list */
         ltrim = llen;

src/t_zset.c

@@ -497,9 +497,9 @@ void zremrangebyrankCommand(redisClient *c) {
     if (start < 0) start = llen+start;
     if (end < 0) end = llen+end;
     if (start < 0) start = 0;
-    if (end < 0) end = 0;
 
-    /* indexes sanity checks */
+    /* Invariant: start >= 0, so this test will be true when end < 0.
+     * The range is empty when start > end or start >= length. */
     if (start > end || start >= llen) {
         addReply(c,shared.czero);
         return;
@@ -750,11 +750,10 @@ void zrangeGenericCommand(redisClient *c, int reverse) {
     if (start < 0) start = llen+start;
     if (end < 0) end = llen+end;
     if (start < 0) start = 0;
-    if (end < 0) end = 0;
 
-    /* indexes sanity checks */
+    /* Invariant: start >= 0, so this test will be true when end < 0.
+     * The range is empty when start > end or start >= length. */
     if (start > end || start >= llen) {
-        /* Out of range start or start > end result in empty list */
         addReply(c,shared.emptymultibulk);
         return;
     }