From 6f5e8f0f398e624b51bec54541833b27c1c139ea Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=B6ren=20Tempel?= <soeren+git@soeren-tempel.net>
Date: Tue, 4 Jun 2019 19:50:23 +0200
Subject: [PATCH] Fix backtracing bug with mpc_parse_pipe

Before we free our buffer we need to reset the underlying stream to its
original state by pushing the buffer contents back onto the input
stream.

Fixes #109
---
 mpc.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/mpc.c b/mpc.c
index 9856efa..87aac4c 100644
--- a/mpc.c
+++ b/mpc.c
@@ -320,6 +320,7 @@ static void mpc_input_mark(mpc_input_t *i) {
 }
 
 static void mpc_input_unmark(mpc_input_t *i) {
+  int j;
 
   if (i->backtrack < 1) { return; }
 
@@ -335,6 +336,9 @@ static void mpc_input_unmark(mpc_input_t *i) {
   }
 
   if (i->type == MPC_INPUT_PIPE && i->marks_num == 0) {
+    for (j = strlen(i->buffer) - 1; j >= 0; j--)
+      ungetc(i->buffer[j], i->file);
+
     free(i->buffer);
     i->buffer = NULL;
   }