X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/a3221d2ac14255c31109a617c4d62b949cd910de..a255c592e8fa9e4570ebbf333e95a402f9e84a03:/match.c

diff --git a/match.c b/match.c
index f3858e5b..b9336b86 100644
--- a/match.c
+++ b/match.c
@@ -24,6 +24,7 @@ extern int am_server;
 extern int do_progress;
 extern int checksum_seed;
 extern int inplace;
+extern int make_backups;
 
 typedef unsigned short tag;
 
@@ -141,11 +142,12 @@ static void matched(int f,struct sum_struct *s,struct map_struct *buf,
 static void hash_search(int f,struct sum_struct *s,
 			struct map_struct *buf, OFF_T len)
 {
-	OFF_T offset, end;
+	OFF_T offset, end, backup;
 	unsigned int k;
 	size_t want_i;
 	char sum2[SUM_LENGTH];
 	uint32 s1, s2, sum;
+	int more;
 	schar *map;
 
 	/* want_i is used to encourage adjacent matches, allowing the RLL
@@ -203,7 +205,7 @@ static void hash_search(int f,struct sum_struct *s,
 
 			/* inplace: ensure chunk's offset is either >= our
 			 * offset or that the data didn't move. */
-			if (inplace && s->sums[i].offset < offset
+			if (inplace && !make_backups && s->sums[i].offset < offset
 			    && !(s->sums[i].flags & SUMFLG_SAME_OFFSET))
 				continue;
 
@@ -225,7 +227,7 @@ static void hash_search(int f,struct sum_struct *s,
 			/* If inplace is enabled, the best possible match is
 			 * one with an identical offset, so we prefer that over
 			 * the following want_i optimization. */
-			if (inplace) {
+			if (inplace && !make_backups) {
 				do {
 					size_t i2 = targets[j].i;
 					if (s->sums[i2].offset != offset)
@@ -248,7 +250,7 @@ static void hash_search(int f,struct sum_struct *s,
 			/* we've found a match, but now check to see
 			 * if want_i can hint at a better match. */
 			if (i != want_i && want_i < s->count
-			    && (!inplace || s->sums[want_i].offset >= offset
+			    && (!inplace || make_backups || s->sums[want_i].offset >= offset
 			     || s->sums[want_i].flags & SUMFLG_SAME_OFFSET)
 			    && sum == s->sums[want_i].sum1
 			    && memcmp(sum2, s->sums[want_i].sum2, s->s2length) == 0) {
@@ -271,14 +273,21 @@ static void hash_search(int f,struct sum_struct *s,
 		} while (++j < s->count && targets[j].t == t);
 
 	null_tag:
+		backup = offset - last_match;
+		/* We sometimes read 1 byte prior to last_match... */
+		if (backup < 0)
+			backup = 0;
+
 		/* Trim off the first byte from the checksum */
-		map = (schar *)map_ptr(buf, offset, k+1);
+		more = offset + k < len;
+		map = (schar *)map_ptr(buf, offset - backup, k + more + backup)
+		    + backup;
 		s1 -= map[0] + CHAR_OFFSET;
 		s2 -= k * (map[0]+CHAR_OFFSET);
 
 		/* Add on the next byte (if there is one) to the checksum */
-		if (k < (len-offset)) {
-			s1 += (map[k]+CHAR_OFFSET);
+		if (more) {
+			s1 += map[k] + CHAR_OFFSET;
 			s2 += s1;
 		} else
 			--k;
@@ -289,9 +298,8 @@ static void hash_search(int f,struct sum_struct *s,
 		   match. The 3 reads are caused by the
 		   running match, the checksum update and the
 		   literal send. */
-		if (offset > last_match
-		 && offset-last_match >= CHUNK_SIZE+s->blength
-		 && end-offset > CHUNK_SIZE) {
+		if (backup >= CHUNK_SIZE + s->blength
+		    && end - offset > CHUNK_SIZE) {
 			matched(f,s,buf,offset - s->blength, -2);
 		}
 	} while (++offset < end);