Implemented an extended-flag-byte in the transfer protocol by moving

the SAME_RDEV bit into the next 8 bits and adding an EXTENDED_FLAG
bit.  Also modified the meaning of this bit for protocol 28 and above:
SAME_HIGH_RDEV indicates that all but the lowest byte matches.  The
older protocols get OLD_SAME_RDEV set (with the old semantics) for
compatibility.  Note also that protocol 28 isn't turned on yet.

diff --git a/flist.c b/flist.c
index 25db1d2..0f4c88f 100644 (file)
--- a/flist.c
+++ b/flist.c
@@ -382,10 +382,19 @@ static void send_file_entry(struct file_struct *file, int f,
                flags |= SAME_MODE;
        else
                last_mode = file->mode;
-       if (file->rdev == last_rdev)
-               flags |= SAME_RDEV;
-       else
-               last_rdev = file->rdev;
+       if (preserve_devices) {
+               if (protocol_version < 28) {
+                       if (IS_DEVICE(last_mode) && file->rdev == last_rdev)
+                               flags |= OLD_SAME_RDEV|SAME_HIGH_RDEV;
+                       else
+                               last_rdev = file->rdev;
+               }
+               else if (IS_DEVICE(last_mode)) {
+                       if ((file->rdev & ~0xFF) == (last_rdev & ~0xFF))
+                               flags |= SAME_HIGH_RDEV;
+                       last_rdev = file->rdev;
+               }
+       }
        if (file->uid == last_uid)
                flags |= SAME_UID;
        else
@@ -409,14 +418,22 @@ static void send_file_entry(struct file_struct *file, int f,
        if (l2 > 255)
                flags |= LONG_NAME;
 
-       /* we must make sure we don't send a zero flags byte or the other
-          end will terminate the flist transfer */
+       /* We must make sure we don't send a zero flags byte or
+        * the other end will terminate the flist transfer. */
        if (flags == 0 && !S_ISDIR(last_mode))
-               flags |= FLAG_DELETE;
-       if (flags == 0)
-               flags |= LONG_NAME;
-
-       write_byte(f, flags);
+               flags |= FLAG_DELETE; /* NOTE: no meaning for non-dir */
+       if (protocol_version >= 28) {
+               if ((flags & 0xFF00) || flags == 0) {
+                       flags |= EXTENDED_FLAGS;
+                       write_byte(f, flags);
+                       write_byte(f, flags >> 8);
+               } else
+                       write_byte(f, flags);
+       } else {
+               if (flags == 0)
+                       flags |= LONG_NAME;
+               write_byte(f, flags);
+       }
        if (flags & SAME_NAME)
                write_byte(f, l1);
        if (flags & LONG_NAME)
@@ -438,9 +455,13 @@ static void send_file_entry(struct file_struct *file, int f,
                add_gid(last_gid);
                write_int(f, last_gid);
        }
-       if (preserve_devices && IS_DEVICE(last_mode)
-           && !(flags & SAME_RDEV))
-               write_int(f, last_rdev);
+       if (preserve_devices && IS_DEVICE(last_mode)) {
+               /* If SAME_HIGH_RDEV is off, OLD_SAME_RDEV is also off. */
+               if (!(flags & SAME_HIGH_RDEV))
+                       write_int(f, last_rdev);
+               else if (protocol_version >= 28)
+                       write_byte(f, last_rdev);
+       }
 
 #if SUPPORT_LINKS
        if (preserve_links && S_ISLNK(last_mode)) {
@@ -564,13 +585,22 @@ static void receive_file_entry(struct file_struct **fptr,
                file->gid = last_gid;
        }
        if (preserve_devices) {
-               if (IS_DEVICE(last_mode)) {
-                       if (!(flags & SAME_RDEV))
+               if (protocol_version < 28) {
+                       if (IS_DEVICE(last_mode)) {
+                               if (!(flags & OLD_SAME_RDEV))
+                                       last_rdev = (DEV64_T)read_int(f);
+                               file->rdev = last_rdev;
+                       } else
+                               last_rdev = 0;
+               } else if (IS_DEVICE(last_mode)) {
+                       if (!(flags & SAME_HIGH_RDEV))
                                last_rdev = (DEV64_T)read_int(f);
+                       else {
+                               last_rdev = (DEV64_T)((last_rdev & ~0xFF)
+                                                       | read_byte(f));
+                       }
                        file->rdev = last_rdev;
                }
-               else
-                       last_rdev = 0;
        }
 
        if (preserve_links && S_ISLNK(last_mode)) {
@@ -1112,6 +1142,8 @@ struct file_list *recv_file_list(int f)
 
                flist_expand(flist);
 
+               if (protocol_version >= 28 && (flags & EXTENDED_FLAGS))
+                       flags |= read_byte(f) << 8;
                receive_file_entry(&flist->files[i], flags, f);
 
                if (S_ISREG(flist->files[i]->mode))