From 3496d7ce2f698bb2e741cbf8d06537e23216facf Mon Sep 17 00:00:00 2001
From: Gabriel Scherer <gabriel.scherer@gmail.com>
Date: Mon, 30 Mar 2015 14:12:23 +0200
Subject: [PATCH] PR#6824: fix buffer sharing on partial application of
 Format.asprintf

TODO Changes
---
 stdlib/format.ml | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/stdlib/format.ml b/stdlib/format.ml
index 5e206e1..1d196a5 100644
--- a/stdlib/format.ml
+++ b/stdlib/format.ml
@@ -976,6 +976,12 @@ let flush_str_formatter () =
   s
 ;;

+let flush_buf_formatter buf ppf =
+  pp_flush_queue ppf false;
+  let s = Buffer.contents buf in
+  Buffer.reset buf;
+  s
+
 (**************************************************************

   Basic functions on the standard formatter
@@ -1176,12 +1182,11 @@ let printf fmt = fprintf std_formatter fmt
 let eprintf fmt = fprintf err_formatter fmt

 let ksprintf k (Format (fmt, _)) =
+  let b = Buffer.create 512 in
+  let ppf = formatter_of_buffer b in
   let k' () acc =
-    let b = Buffer.create 512 in
-    let ppf = formatter_of_buffer b in
     strput_acc ppf acc;
-    pp_flush_queue ppf false;
-    k (Buffer.contents b) in
+    k (flush_buf_formatter b ppf) in
   make_printf k' () End_of_acc fmt

 let sprintf fmt =
@@ -1194,7 +1199,7 @@ let asprintf (Format (fmt, _)) =
     = fun ppf acc ->
       output_acc ppf acc;
       pp_flush_queue ppf false;
-      Buffer.contents b in
+      flush_buf_formatter b ppf in
   make_printf k' ppf End_of_acc fmt

 (**************************************************************
--
2.1.4