commit 416e719bea4f5466c8dd2b34cac0059b6ff84ff3
Author: Wayne Davison <wayned@samba.org>
Date:   Tue Nov 7 14:01:13 2017 -0800

    More archaic-checksum improvements. This makes the len vars clearer
    and ensures that only the flist code gets the 2-byte digest len.

diff --git a/authenticate.c b/authenticate.c
index 519429d..d60ee20 100644
--- a/authenticate.c
+++ b/authenticate.c
@@ -74,8 +74,6 @@ static void gen_challenge(const char *addr, char *challenge)
 	sum_init(-1, 0);
 	sum_update(input, sizeof input);
 	len = sum_end(digest);
-	if (len == 2) /* The archaic checksum is 2 bytes, but sum_end() filled in the full MD4 checksum for us. */
-		len = MD4_DIGEST_LEN;
 
 	base64_encode(digest, len, challenge, 0);
 }
@@ -91,8 +89,6 @@ static void generate_hash(const char *in, const char *challenge, char *out)
 	sum_update(in, strlen(in));
 	sum_update(challenge, strlen(challenge));
 	len = sum_end(buf);
-	if (len == 2) /* The archaic checksum is 2 bytes, but sum_end() filled in the full MD4 checksum for us. */
-		len = MD4_DIGEST_LEN;
 
 	base64_encode(buf, len, out, 0);
 }
diff --git a/checksum.c b/checksum.c
index 741ad7d..4c9351c 100644
--- a/checksum.c
+++ b/checksum.c
@@ -73,13 +73,15 @@ int parse_csum_name(const char *name, int len)
 	exit_cleanup(RERR_UNSUPPORTED);
 }
 
-int csum_len_for_type(int cst)
+int csum_len_for_type(int cst, int flist_csum)
 {
 	switch (cst) {
 	  case CSUM_NONE:
 		return 1;
 	  case CSUM_MD4_ARCHAIC:
-		return 2;
+		/* The oldest checksum code is rather weird: the file-list code only sent
+		 * 2-byte checksums, but all other checksums were full MD4 length. */
+		return flist_csum ? 2 : MD4_DIGEST_LEN;
 	  case CSUM_MD4:
 	  case CSUM_MD4_OLD:
 	  case CSUM_MD4_BUSTED:
@@ -361,5 +363,5 @@ int sum_end(char *sum)
 		exit_cleanup(RERR_UNSUPPORTED);
 	}
 
-	return csum_len_for_type(cursum_type);
+	return csum_len_for_type(cursum_type, 0);
 }
diff --git a/flist.c b/flist.c
index 24b3506..bedba63 100644
--- a/flist.c
+++ b/flist.c
@@ -91,7 +91,7 @@ extern iconv_t ic_send, ic_recv;
 #define PTR_SIZE (sizeof (struct file_struct *))
 
 int io_error;
-int checksum_len;
+int flist_csum_len;
 dev_t filesystem_dev; /* used to implement -x */
 
 struct file_list *cur_flist, *first_flist, *dir_flist;
@@ -141,7 +141,7 @@ void init_flist(void)
 			(int)FILE_STRUCT_LEN, (int)EXTRA_LEN);
 	}
 	parse_checksum_choice(); /* Sets checksum_type && xfersum_type */
-	checksum_len = csum_len_for_type(checksum_type);
+	flist_csum_len = csum_len_for_type(checksum_type, 1);
 
 	show_filelist_progress = INFO_GTE(FLIST, 1) && xfer_dirs && !am_server && !inc_recurse;
 }
@@ -638,7 +638,7 @@ static void send_file_entry(int f, const char *fname, struct file_struct *file,
 			/* Prior to 28, we sent a useless set of nulls. */
 			sum = empty_sum;
 		}
-		write_buf(f, sum, checksum_len);
+		write_buf(f, sum, flist_csum_len);
 	}
 
 #ifdef SUPPORT_HARD_LINKS
@@ -1094,9 +1094,9 @@ static struct file_struct *recv_file_entry(int f, struct file_list *flist, int x
 		}
 		if (first_hlink_ndx >= flist->ndx_start) {
 			struct file_struct *first = flist->files[first_hlink_ndx - flist->ndx_start];
-			memcpy(bp, F_SUM(first), checksum_len);
+			memcpy(bp, F_SUM(first), flist_csum_len);
 		} else
-			read_buf(f, bp, checksum_len);
+			read_buf(f, bp, flist_csum_len);
 	}
 
 #ifdef SUPPORT_ACLS
@@ -1384,7 +1384,7 @@ struct file_struct *make_file(const char *fname, struct file_list *flist,
 	}
 
 	if (sender_keeps_checksum && S_ISREG(st.st_mode))
-		memcpy(F_SUM(file), tmp_sum, checksum_len);
+		memcpy(F_SUM(file), tmp_sum, flist_csum_len);
 
 	if (unsort_ndx)
 		F_NDX(file) = stats.num_dirs;
diff --git a/generator.c b/generator.c
index af2e290..3d65839 100644
--- a/generator.c
+++ b/generator.c
@@ -74,7 +74,7 @@ extern int protocol_version;
 extern int file_total;
 extern int fuzzy_basis;
 extern int always_checksum;
-extern int checksum_len;
+extern int flist_csum_len;
 extern char *partial_dir;
 extern int compare_dest;
 extern int copy_dest;
@@ -583,7 +583,7 @@ int unchanged_file(char *fn, struct file_struct *file, STRUCT_STAT *st)
 	if (always_checksum > 0 && S_ISREG(st->st_mode)) {
 		char sum[MAX_DIGEST_LEN];
 		file_checksum(fn, st, sum);
-		return memcmp(sum, F_SUM(file), checksum_len) == 0;
+		return memcmp(sum, F_SUM(file), flist_csum_len) == 0;
 	}
 
 	if (size_only > 0)
diff --git a/log.c b/log.c
index b145ee1..7b23a2c 100644
--- a/log.c
+++ b/log.c
@@ -673,14 +673,15 @@ static void log_formatted(enum logcode code, const char *format, const char *op,
 			n = NULL;
 			if (S_ISREG(file->mode)) {
 				if (always_checksum && canonical_checksum(checksum_type))
-					n = sum_as_hex(checksum_type, F_SUM(file));
+					n = sum_as_hex(checksum_type, F_SUM(file), 1);
 				else if (iflags & ITEM_TRANSFER && canonical_checksum(xfersum_type))
-					n = sum_as_hex(xfersum_type, sender_file_sum);
+					n = sum_as_hex(xfersum_type, sender_file_sum, 0);
 			}
 			if (!n) {
-				int checksum_len = csum_len_for_type(always_checksum ? checksum_type : xfersum_type);
-				memset(buf2, ' ', checksum_len*2);
-				buf2[checksum_len*2] = '\0';
+				int sum_len = csum_len_for_type(always_checksum ? checksum_type : xfersum_type,
+								always_checksum);
+				memset(buf2, ' ', sum_len*2);
+				buf2[sum_len*2] = '\0';
 				n = buf2;
 			}
 			break;
diff --git a/match.c b/match.c
index ff10310..280038b 100644
--- a/match.c
+++ b/match.c
@@ -360,7 +360,7 @@ static void hash_search(int f,struct sum_struct *s,
  **/
 void match_sums(int f, struct sum_struct *s, struct map_struct *buf, OFF_T len)
 {
-	int checksum_len;
+	int sum_len;
 
 	last_match = 0;
 	false_alarms = 0;
@@ -409,22 +409,22 @@ void match_sums(int f, struct sum_struct *s, struct map_struct *buf, OFF_T len)
 		matched(f, s, buf, len, -1);
 	}
 
-	checksum_len = sum_end(sender_file_sum);
+	sum_len = sum_end(sender_file_sum);
 
 	/* If we had a read error, send a bad checksum.  We use all bits
 	 * off as long as the checksum doesn't happen to be that, in
 	 * which case we turn the last 0 bit into a 1. */
 	if (buf && buf->status != 0) {
 		int i;
-		for (i = 0; i < checksum_len && sender_file_sum[i] == 0; i++) {}
-		memset(sender_file_sum, 0, checksum_len);
-		if (i == checksum_len)
+		for (i = 0; i < sum_len && sender_file_sum[i] == 0; i++) {}
+		memset(sender_file_sum, 0, sum_len);
+		if (i == sum_len)
 			sender_file_sum[i-1]++;
 	}
 
 	if (DEBUG_GTE(DELTASUM, 2))
 		rprintf(FINFO,"sending file_sum\n");
-	write_buf(f, sender_file_sum, checksum_len);
+	write_buf(f, sender_file_sum, sum_len);
 
 	if (DEBUG_GTE(DELTASUM, 2)) {
 		rprintf(FINFO, "false_alarms=%d hash_hits=%d matches=%d\n",
diff --git a/receiver.c b/receiver.c
index 3d9bc65..baae3a9 100644
--- a/receiver.c
+++ b/receiver.c
@@ -236,7 +236,7 @@ static int receive_data(int f_in, char *fname_r, int fd_r, OFF_T size_r,
 	static char file_sum1[MAX_DIGEST_LEN];
 	struct map_struct *mapbuf;
 	struct sum_struct sum;
-	int checksum_len;
+	int sum_len;
 	int32 len;
 	OFF_T offset = 0;
 	OFF_T offset2;
@@ -388,15 +388,15 @@ static int receive_data(int f_in, char *fname_r, int fd_r, OFF_T size_r,
 	if (INFO_GTE(PROGRESS, 1))
 		end_progress(total_size);
 
-	checksum_len = sum_end(file_sum1);
+	sum_len = sum_end(file_sum1);
 
 	if (mapbuf)
 		unmap_file(mapbuf);
 
-	read_buf(f_in, sender_file_sum, checksum_len);
+	read_buf(f_in, sender_file_sum, sum_len);
 	if (DEBUG_GTE(DELTASUM, 2))
 		rprintf(FINFO,"got file_sum\n");
-	if (fd != -1 && memcmp(file_sum1, sender_file_sum, checksum_len) != 0)
+	if (fd != -1 && memcmp(file_sum1, sender_file_sum, sum_len) != 0)
 		return 0;
 	return 1;
 }
diff --git a/t_stub.c b/t_stub.c
index fc1ee3b..0c49d9c 100644
--- a/t_stub.c
+++ b/t_stub.c
@@ -98,7 +98,7 @@ filter_rule_list daemon_filter_list;
 	return "tester";
 }
 
- int csum_len_for_type(int cst)
+ int csum_len_for_type(int cst, int flg)
 {
-	return cst ? 16 : 1;
+	return cst || !flg ? 16 : 1;
 }
diff --git a/util2.c b/util2.c
index a892e51..b1adf81 100644
--- a/util2.c
+++ b/util2.c
@@ -77,18 +77,18 @@ void *_realloc_array(void *ptr, unsigned int size, size_t num)
 	return realloc(ptr, size * num);
 }
 
-const char *sum_as_hex(int csum_type, const char *sum)
+const char *sum_as_hex(int csum_type, const char *sum, int flist_csum)
 {
 	static char buf[MAX_DIGEST_LEN*2+1];
 	int i, x1, x2;
-	int checksum_len = csum_len_for_type(csum_type);
-	char *c = buf + checksum_len*2;
+	int sum_len = csum_len_for_type(csum_type, flist_csum);
+	char *c = buf + sum_len*2;
 
 	assert(c - buf < (int)sizeof buf);
 
 	*c = '\0';
 
-	for (i = checksum_len; --i >= 0; ) {
+	for (i = sum_len; --i >= 0; ) {
 		x1 = CVAL(sum, i);
 		x2 = x1 >> 4;
 		x1 &= 0xF;