[Monotone-debian] Bug#574562: monotone-viz incompatible with monotone version in unstable

[Francis Russell]

I've attached a patch I was sent from the author of the new stdio
changes for monotone-viz, Stéphane Gimenez against revision
142b487d0b2cc5e24e17998407f7921f2372ea3c in the
net.venge.monotone-viz.new-stdio branch that fixes a error with parsing
the monotone "format-version" line I encountered. I assume this patch
will make it into the new-stdio branch anyway but currently it isn't, so
I decided to forward it here.

Regards,

Francis

#
# old_revision [142b487d0b2cc5e24e17998407f7921f2372ea3c]
#
# patch "automate.ml"
#  from [62bef3827396107a9fb8c65ac340cfda00abe7a0]
#    to [81cd3139b4ac5a13091737bf47b0c2e1b62eea62]
#
============================================================
--- automate.ml 62bef3827396107a9fb8c65ac340cfda00abe7a0
+++ automate.ml 81cd3139b4ac5a13091737bf47b0c2e1b62eea62
@@ -407,20 +407,20 @@ let spawn mtn db = 
       chunks = [] ;
       exit_cb = (fun _ -> assert false)
     } in
-  let head = String.create 4096 in
-  while not (String.contains head '\n') do
-      match Giochannel.read_chars p.p_out.out_w.w_chan head with
-      | `NORMAL read -> ()
+  let rec check_version buf =
+    if String.contains buf '\n' then
+      String.length buf >= 18 && String.sub buf 0 18 = "format-version: 2\n"
+    else
+      match Giochannel.read_chars p.p_out.out_w.w_chan p.p_out.out_sb  with
+      | `NORMAL read -> check_version (buf ^ String.sub p.p_out.out_sb 0 read)
       | `EOF ->
          Giochannel.shutdown p.p_out.out_w.w_chan false;
          Giochannel.shutdown p.p_err.out_w.w_chan false;
          failwith "mtn version 0.46 or above is required";
-      | `AGAIN -> ()
-  done;
-  let accept =
-    String.length head > 18 && String.sub head 0 18 = "format-version: 2\n"
+      | `AGAIN -> check_version buf
   in
-  if not accept then failwith "mtn stdio uses an unknown format-version";
+  if not (check_version "")
+  then failwith "mtn stdio uses an unknown format-version";
   let pid = some child.Gspawn.pid in
   ignore (Gspawn.add_child_watch ~prio:50 pid (reap_cb p pid)) ;
   p.p_out.out_cb <- out_cb p ;