X-Git-Url: https://git.saurik.com/redis.git/blobdiff_plain/5117c20ab5558e5d68b1a3c7751610cd6c4279db..7eb850ef0e437323e2d84157ddc2e6e82af57bbc:/src/ziplist.c?ds=sidebyside diff --git a/src/ziplist.c b/src/ziplist.c index 8ada7c42..23bad45c 100644 --- a/src/ziplist.c +++ b/src/ziplist.c @@ -500,12 +500,13 @@ static unsigned char *__ziplistDelete(unsigned char *zl, unsigned char *p, unsig totlen = p-first.p; if (totlen > 0) { if (p[0] != ZIP_END) { - /* Tricky: storing the prevlen in this entry might reduce or - * increase the number of bytes needed, compared to the current - * prevlen. Note that we can always store this length because - * it was previously stored by an entry that is being deleted. */ + /* Storing `prevrawlen` in this entry may increase or decrease the + * number of bytes required compare to the current `prevrawlen`. + * There always is room to store this, because it was previously + * stored by an entry that is now being deleted. */ nextdiff = zipPrevLenByteDiff(p,first.prevrawlen); - zipPrevEncodeLength(p-nextdiff,first.prevrawlen); + p -= nextdiff; + zipPrevEncodeLength(p,first.prevrawlen); /* Update offset for tail */ ZIPLIST_TAIL_OFFSET(zl) = @@ -521,8 +522,8 @@ static unsigned char *__ziplistDelete(unsigned char *zl, unsigned char *p, unsig } /* Move tail to the front of the ziplist */ - memmove(first.p,p-nextdiff, - intrev32ifbe(ZIPLIST_BYTES(zl))-(p-zl)-1+nextdiff); + memmove(first.p,p, + intrev32ifbe(ZIPLIST_BYTES(zl))-(p-zl)-1); } else { /* The entire tail was deleted. No need to move memory. */ ZIPLIST_TAIL_OFFSET(zl) =