fix unexpected behavior on an out of range end index for LRANGE and LTRIM

[redis.git] / redis.c

diff --git a/redis.c b/redis.c
index 8f5e8f47f43bce8ec5502f479a6b147171b9cf69..085d35532a8f4bc1ed3dec83a9829b8fdb072b99 100644 (file)
--- a/redis.c
+++ b/redis.c
@@ -77,7 +77,6 @@
 #include "zipmap.h" /* Compact dictionary-alike data structure */
 #include "ziplist.h" /* Compact list data structure */
 #include "sha1.h"   /* SHA1 is used for DEBUG DIGEST */
-#include "release.h" /* Release and/or git repository information */
 
 /* Error codes */
 #define REDIS_OK                0
@@ -130,11 +129,11 @@
 #define REDIS_ENCODING_INT 1     /* Encoded as integer */
 #define REDIS_ENCODING_HT 2      /* Encoded as hash table */
 #define REDIS_ENCODING_ZIPMAP 3  /* Encoded as zipmap */
-#define REDIS_ENCODING_LIST 4    /* Encoded as zipmap */
+#define REDIS_ENCODING_LINKEDLIST 4 /* Encoded as regular linked list */
 #define REDIS_ENCODING_ZIPLIST 5 /* Encoded as ziplist */
 
 static char* strencoding[] = {
-    "raw", "int", "hashtable", "zipmap", "list", "ziplist"
+    "raw", "int", "hashtable", "zipmap", "linkedlist", "ziplist"
 };
 
 /* Object types only used for dumping to disk */
@@ -3060,7 +3059,7 @@ static robj *createListObject(void) {
     list *l = listCreate();
     robj *o = createObject(REDIS_LIST,l);
     listSetFreeMethod(l,decrRefCount);
-    o->encoding = REDIS_ENCODING_LIST;
+    o->encoding = REDIS_ENCODING_LINKEDLIST;
     return o;
 }
 
@@ -3102,7 +3101,7 @@ static void freeStringObject(robj *o) {
 
 static void freeListObject(robj *o) {
     switch (o->encoding) {
-    case REDIS_ENCODING_LIST:
+    case REDIS_ENCODING_LINKEDLIST:
         listRelease((list*) o->ptr);
         break;
     case REDIS_ENCODING_ZIPLIST:
@@ -3778,7 +3777,7 @@ static int rdbSaveObject(FILE *fp, robj *o) {
                 }
                 p = ziplistNext(o->ptr,p);
             }
-        } else if (o->encoding == REDIS_ENCODING_LIST) {
+        } else if (o->encoding == REDIS_ENCODING_LINKEDLIST) {
             list *list = o->ptr;
             listIter li;
             listNode *ln;
@@ -4188,7 +4187,7 @@ static robj *rdbLoadObject(int type, FILE *fp) {
             if (o->encoding == REDIS_ENCODING_ZIPLIST &&
                 ele->encoding == REDIS_ENCODING_RAW &&
                 sdslen(ele->ptr) > server.list_max_ziplist_value)
-                    listTypeConvert(o,REDIS_ENCODING_LIST);
+                    listTypeConvert(o,REDIS_ENCODING_LINKEDLIST);
 
             if (o->encoding == REDIS_ENCODING_ZIPLIST) {
                 dec = getDecodedObject(ele);
@@ -4928,7 +4927,7 @@ static void listTypeTryConversion(robj *subject, robj *value) {
     if (subject->encoding != REDIS_ENCODING_ZIPLIST) return;
     if (value->encoding == REDIS_ENCODING_RAW &&
         sdslen(value->ptr) > server.list_max_ziplist_value)
-            listTypeConvert(subject,REDIS_ENCODING_LIST);
+            listTypeConvert(subject,REDIS_ENCODING_LINKEDLIST);
 }
 
 static void listTypePush(robj *subject, robj *value, int where) {
@@ -4936,14 +4935,14 @@ static void listTypePush(robj *subject, robj *value, int where) {
     listTypeTryConversion(subject,value);
     if (subject->encoding == REDIS_ENCODING_ZIPLIST &&
         ziplistLen(subject->ptr) >= server.list_max_ziplist_entries)
-            listTypeConvert(subject,REDIS_ENCODING_LIST);
+            listTypeConvert(subject,REDIS_ENCODING_LINKEDLIST);
 
     if (subject->encoding == REDIS_ENCODING_ZIPLIST) {
         int pos = (where == REDIS_HEAD) ? ZIPLIST_HEAD : ZIPLIST_TAIL;
         value = getDecodedObject(value);
         subject->ptr = ziplistPush(subject->ptr,value->ptr,sdslen(value->ptr),pos);
         decrRefCount(value);
-    } else if (subject->encoding == REDIS_ENCODING_LIST) {
+    } else if (subject->encoding == REDIS_ENCODING_LINKEDLIST) {
         if (where == REDIS_HEAD) {
             listAddNodeHead(subject->ptr,value);
         } else {
@@ -4973,7 +4972,7 @@ static robj *listTypePop(robj *subject, int where) {
             /* We only need to delete an element when it exists */
             subject->ptr = ziplistDelete(subject->ptr,&p);
         }
-    } else if (subject->encoding == REDIS_ENCODING_LIST) {
+    } else if (subject->encoding == REDIS_ENCODING_LINKEDLIST) {
         list *list = subject->ptr;
         listNode *ln;
         if (where == REDIS_HEAD) {
@@ -4995,7 +4994,7 @@ static robj *listTypePop(robj *subject, int where) {
 static unsigned long listTypeLength(robj *subject) {
     if (subject->encoding == REDIS_ENCODING_ZIPLIST) {
         return ziplistLen(subject->ptr);
-    } else if (subject->encoding == REDIS_ENCODING_LIST) {
+    } else if (subject->encoding == REDIS_ENCODING_LINKEDLIST) {
         return listLength((list*)subject->ptr);
     } else {
         redisPanic("Unknown list encoding");
@@ -5026,7 +5025,7 @@ static listTypeIterator *listTypeInitIterator(robj *subject, int index, unsigned
     li->direction = direction;
     if (li->encoding == REDIS_ENCODING_ZIPLIST) {
         li->zi = ziplistIndex(subject->ptr,index);
-    } else if (li->encoding == REDIS_ENCODING_LIST) {
+    } else if (li->encoding == REDIS_ENCODING_LINKEDLIST) {
         li->ln = listIndex(subject->ptr,index);
     } else {
         redisPanic("Unknown list encoding");
@@ -5056,7 +5055,7 @@ static int listTypeNext(listTypeIterator *li, listTypeEntry *entry) {
                 li->zi = ziplistPrev(li->subject->ptr,li->zi);
             return 1;
         }
-    } else if (li->encoding == REDIS_ENCODING_LIST) {
+    } else if (li->encoding == REDIS_ENCODING_LINKEDLIST) {
         entry->ln = li->ln;
         if (entry->ln != NULL) {
             if (li->direction == REDIS_TAIL)
@@ -5087,7 +5086,7 @@ static robj *listTypeGet(listTypeEntry *entry) {
                 value = createStringObjectFromLongLong(vlong);
             }
         }
-    } else if (li->encoding == REDIS_ENCODING_LIST) {
+    } else if (li->encoding == REDIS_ENCODING_LINKEDLIST) {
         redisAssert(entry->ln != NULL);
         value = listNodeValue(entry->ln);
         incrRefCount(value);
@@ -5115,7 +5114,7 @@ static void listTypeInsert(listTypeEntry *entry, robj *value, int where) {
             subject->ptr = ziplistInsert(subject->ptr,entry->zi,value->ptr,sdslen(value->ptr));
         }
         decrRefCount(value);
-    } else if (entry->li->encoding == REDIS_ENCODING_LIST) {
+    } else if (entry->li->encoding == REDIS_ENCODING_LINKEDLIST) {
         if (where == REDIS_TAIL) {
             listInsertNode(subject->ptr,entry->ln,value,AL_START_TAIL);
         } else {
@@ -5133,7 +5132,7 @@ static int listTypeEqual(listTypeEntry *entry, robj *o) {
     if (li->encoding == REDIS_ENCODING_ZIPLIST) {
         redisAssert(o->encoding == REDIS_ENCODING_RAW);
         return ziplistCompare(entry->zi,o->ptr,sdslen(o->ptr));
-    } else if (li->encoding == REDIS_ENCODING_LIST) {
+    } else if (li->encoding == REDIS_ENCODING_LINKEDLIST) {
         return equalStringObjects(o,listNodeValue(entry->ln));
     } else {
         redisPanic("Unknown list encoding");
@@ -5152,7 +5151,7 @@ static void listTypeDelete(listTypeEntry *entry) {
             li->zi = p;
         else
             li->zi = ziplistPrev(li->subject->ptr,p);
-    } else if (entry->li->encoding == REDIS_ENCODING_LIST) {
+    } else if (entry->li->encoding == REDIS_ENCODING_LINKEDLIST) {
         listNode *next;
         if (li->direction == REDIS_TAIL)
             next = entry->ln->next;
@@ -5170,7 +5169,7 @@ static void listTypeConvert(robj *subject, int enc) {
     listTypeEntry entry;
     redisAssert(subject->type == REDIS_LIST);
 
-    if (enc == REDIS_ENCODING_LIST) {
+    if (enc == REDIS_ENCODING_LINKEDLIST) {
         list *l = listCreate();
         listSetFreeMethod(l,decrRefCount);
 
@@ -5179,7 +5178,7 @@ static void listTypeConvert(robj *subject, int enc) {
         while (listTypeNext(li,&entry)) listAddNodeTail(l,listTypeGet(&entry));
         listTypeReleaseIterator(li);
 
-        subject->encoding = REDIS_ENCODING_LIST;
+        subject->encoding = REDIS_ENCODING_LINKEDLIST;
         zfree(subject->ptr);
         subject->ptr = l;
     } else {
@@ -5255,7 +5254,7 @@ static void pushxGenericCommand(redisClient *c, robj *refval, robj *val, int whe
             /* Check if the length exceeds the ziplist length threshold. */
             if (subject->encoding == REDIS_ENCODING_ZIPLIST &&
                 ziplistLen(subject->ptr) > server.list_max_ziplist_entries)
-                    listTypeConvert(subject,REDIS_ENCODING_LIST);
+                    listTypeConvert(subject,REDIS_ENCODING_LINKEDLIST);
             server.dirty++;
         } else {
             /* Notify client of a failed insert */
@@ -5317,7 +5316,7 @@ static void lindexCommand(redisClient *c) {
         } else {
             addReply(c,shared.nullbulk);
         }
-    } else if (o->encoding == REDIS_ENCODING_LIST) {
+    } else if (o->encoding == REDIS_ENCODING_LINKEDLIST) {
         listNode *ln = listIndex(o->ptr,index);
         if (ln != NULL) {
             value = listNodeValue(ln);
@@ -5350,7 +5349,7 @@ static void lsetCommand(redisClient *c) {
             addReply(c,shared.ok);
             server.dirty++;
         }
-    } else if (o->encoding == REDIS_ENCODING_LIST) {
+    } else if (o->encoding == REDIS_ENCODING_LINKEDLIST) {
         listNode *ln = listIndex(o->ptr,index);
         if (ln == NULL) {
             addReply(c,shared.outofrangeerr);
@@ -5405,9 +5404,9 @@ static 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);
@@ -5445,9 +5444,9 @@ static 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;
@@ -5462,7 +5461,7 @@ static void ltrimCommand(redisClient *c) {
     if (o->encoding == REDIS_ENCODING_ZIPLIST) {
         o->ptr = ziplistDeleteRange(o->ptr,0,ltrim);
         o->ptr = ziplistDeleteRange(o->ptr,-rtrim,rtrim);
-    } else if (o->encoding == REDIS_ENCODING_LIST) {
+    } else if (o->encoding == REDIS_ENCODING_LINKEDLIST) {
         list = o->ptr;
         for (j = 0; j < ltrim; j++) {
             ln = listFirst(list);
@@ -6410,9 +6409,9 @@ static 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;
@@ -6663,11 +6662,10 @@ static 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;
     }
@@ -9152,7 +9150,7 @@ static int rewriteAppendOnlyFile(char *filename) {
                         }
                         p = ziplistNext(zl,p);
                     }
-                } else if (o->encoding == REDIS_ENCODING_LIST) {
+                } else if (o->encoding == REDIS_ENCODING_LINKEDLIST) {
                     list *list = o->ptr;
                     listNode *ln;
                     listIter li;