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) =
}
/* 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) =