From f855a7d01ab8401a307bb02cdcdee546df3e2423 Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <tridge@samba.org>
Date: Sat, 26 Jun 1999 01:06:38 +0000
Subject: [PATCH] fixed a bug that made us use only 16 bits of the file
 checksum when comparing checksums for the --checksum (-c) option.

---
 checksum.c  |  2 +-
 compat.c    |  2 --
 flist.c     | 14 ++++++++++----
 generator.c | 24 +++++++++++++++---------
 main.c      |  2 --
 rsync.h     |  2 +-
 6 files changed, 27 insertions(+), 19 deletions(-)

diff --git a/checksum.c b/checksum.c
index edc844f2..194d899a 100644
--- a/checksum.c
+++ b/checksum.c
@@ -91,7 +91,7 @@ void file_checksum(char *fname,char *sum,OFF_T size)
 	char tmpchunk[CSUM_CHUNK];
 	struct mdfour m;
 	
-	memset(sum,0,csum_length);
+	memset(sum,0,MD4_SUM_LENGTH);
 	
 	fd = open(fname,O_RDONLY);
 	if (fd == -1) return;
diff --git a/compat.c b/compat.c
index af72f8b1..ee9e0520 100644
--- a/compat.c
+++ b/compat.c
@@ -23,8 +23,6 @@
 
 extern int am_server;
 
-extern int csum_length;
-
 extern int preserve_links;
 extern int preserve_perms;
 extern int preserve_devices;
diff --git a/flist.c b/flist.c
index c6e0006c..b8b4c666 100644
--- a/flist.c
+++ b/flist.c
@@ -23,8 +23,6 @@
 
 extern struct stats stats;
 
-extern int csum_length;
-
 extern int verbose;
 extern int am_server;
 extern int always_checksum;
@@ -254,7 +252,11 @@ static void send_file_entry(struct file_struct *file,int f,unsigned base_flags)
 #endif
 
 	if (always_checksum) {
-		write_buf(f,file->sum,csum_length);
+		if (remote_version < 21) {
+			write_buf(f,file->sum,2);
+		} else {
+			write_buf(f,file->sum,MD4_SUM_LENGTH);
+		}
 	}       
 
 	last_mode = file->mode;
@@ -353,7 +355,11 @@ static void receive_file_entry(struct file_struct **fptr,
 	if (always_checksum) {
 		file->sum = (char *)malloc(MD4_SUM_LENGTH);
 		if (!file->sum) out_of_memory("md4 sum");
-		read_buf(f,file->sum,csum_length);
+		if (remote_version < 21) {
+			read_buf(f,file->sum,2);
+		} else {
+			read_buf(f,file->sum,MD4_SUM_LENGTH);
+		}
 	}
   
 	last_mode = file->mode;
diff --git a/generator.c b/generator.c
index d77e7b56..bbc328df 100644
--- a/generator.c
+++ b/generator.c
@@ -50,7 +50,11 @@ static int skip_file(char *fname,
 	if (always_checksum && S_ISREG(st->st_mode)) {
 		char sum[MD4_SUM_LENGTH];
 		file_checksum(fname,sum,st->st_size);
-		return (memcmp(sum,file->sum,csum_length) == 0);
+		if (remote_version < 21) {
+			return (memcmp(sum,file->sum,2) == 0);
+		} else {
+			return (memcmp(sum,file->sum,MD4_SUM_LENGTH) == 0);
+		}
 	}
 
 	if (size_only) {
@@ -86,17 +90,19 @@ static int adapt_block_size(struct file_struct *file, int bsize)
 static void send_sums(struct sum_struct *s,int f_out)
 {
 	int i;
-
-  /* tell the other guy how many we are going to be doing and how many
-     bytes there are in the last chunk */
+	
+	/* tell the other guy how many we are going to be doing and how many
+	   bytes there are in the last chunk */
 	write_int(f_out,s?s->count:0);
 	write_int(f_out,s?s->n:block_size);
 	write_int(f_out,s?s->remainder:0);
-	if (s)
-		for (i=0;i<s->count;i++) {
-			write_int(f_out,s->sums[i].sum1);
-			write_buf(f_out,s->sums[i].sum2,csum_length);
-		}
+
+	if (!s) return;
+
+	for (i=0;i<s->count;i++) {
+		write_int(f_out,s->sums[i].sum1);
+		write_buf(f_out,s->sums[i].sum2,csum_length);
+	}
 }
 
 
diff --git a/main.c b/main.c
index db9201af..807409e3 100644
--- a/main.c
+++ b/main.c
@@ -23,8 +23,6 @@ time_t starttime = 0;
 
 struct stats stats;
 
-extern int csum_length;
-
 extern int verbose;
 
 static void report(int f)
diff --git a/rsync.h b/rsync.h
index 32d564cb..03d38dd9 100644
--- a/rsync.h
+++ b/rsync.h
@@ -47,7 +47,7 @@
 #define SAME_TIME (1<<7)
 
 /* update this if you make incompatible changes */
-#define PROTOCOL_VERSION 20
+#define PROTOCOL_VERSION 21
 #define MIN_PROTOCOL_VERSION 11
 #define MAX_PROTOCOL_VERSION 30
 
-- 
2.34.1