From 6ebeef7924dfc503c8d1175dea63cea8d935410a Mon Sep 17 00:00:00 2001
From: Josh Elsasser <josh@elsasser.org>
Date: Sun, 28 Jan 2007 23:26:57 +0000
Subject: [PATCH] Correctly bencode strings containing nul characters.

---
 libtransmission/bencode.c | 11 ++++-------
 libtransmission/utils.c   | 34 +++++++++++++++++++++++++++++-----
 libtransmission/utils.h   |  3 +++
 3 files changed, 36 insertions(+), 12 deletions(-)

diff --git a/libtransmission/bencode.c b/libtransmission/bencode.c
index 58bf94b1b..f3fb472ef 100644
--- a/libtransmission/bencode.c
+++ b/libtransmission/bencode.c
@@ -164,7 +164,8 @@ static void __bencPrint( benc_val_t * val, int space )
             break;
 
         case TYPE_STR:
-            fprintf( stderr, "%s\n", val->val.s.s );
+            fwrite( val->val.s.s, 1, val->val.s.i, stderr );
+            putc( '\n', stderr );
             break;
 
         case TYPE_LIST:
@@ -265,12 +266,8 @@ int tr_bencSave( benc_val_t * val, char ** buf, int * used, int * max )
             break;
 
         case TYPE_STR:
-            if( (int)strlen(val->val.s.s) != val->val.s.i )
-            {
-                return 1;
-            }
-            if( tr_sprintf( buf, used, max, "%i:%s",
-                            val->val.s.i, val->val.s.s ) )
+            if( tr_sprintf( buf, used, max, "%i:", val->val.s.i ) ||
+                tr_concat( buf, used,  max, val->val.s.s, val->val.s.i ) )
             {
                 return 1;
             }
diff --git a/libtransmission/utils.c b/libtransmission/utils.c
index 8acc353b3..2e99190a5 100644
--- a/libtransmission/utils.c
+++ b/libtransmission/utils.c
@@ -300,22 +300,46 @@ int tr_vsprintf( char ** buf, int * used, int * max, const char * fmt,
                  va_list ap1, va_list ap2 )
 {
     int     want;
-    char  * newbuf;
 
     want = vsnprintf( NULL, 0, fmt, ap1 );
 
-    while( *used + want + 1 > *max )
+    if( tr_concat( buf, used, max, NULL, want ) )
     {
-        *max += SPRINTF_BUFSIZE;
-        newbuf = realloc( *buf, *max );
+        return 1;
+    }
+    assert( *used + want + 1 <= *max );
+
+    *used += vsnprintf( *buf + *used, *max - *used, fmt, ap2 );
+
+    return 0;
+}
+
+int tr_concat( char ** buf, int * used, int * max, const char * data, int len )
+{
+    int     newmax;
+    char  * newbuf;
+
+    newmax = *max;
+    while( *used + len + 1 > newmax )
+    {
+        newmax += SPRINTF_BUFSIZE;
+    }
+    if( newmax > *max )
+    {
+        newbuf = realloc( *buf, newmax );
         if( NULL == newbuf )
         {
             return 1;
         }
         *buf = newbuf;
+        *max = newmax;
     }
 
-    *used += vsnprintf( *buf + *used, *max - *used, fmt, ap2 );
+    if( NULL != data )
+    {
+        memcpy( *buf + *used, data, len );
+        *used += len;
+    }
 
     return 0;
 }
diff --git a/libtransmission/utils.h b/libtransmission/utils.h
index dd98fc031..2d778e246 100644
--- a/libtransmission/utils.h
+++ b/libtransmission/utils.h
@@ -62,6 +62,9 @@ int tr_sprintf( char ** buf, int * used, int * max,
                 const char * format, ... ) PRINTF( 4, 5 );
 /* gee, it sure would be nice if BeOS had va_copy() */
 int tr_vsprintf( char **, int *, int *, const char *, va_list, va_list );
+/* this concatenates some binary data onto the end of a buffer */
+int tr_concat( char ** buf, int * used, int * max,
+               const char * data, int len );
 
 /***********************************************************************
  * tr_dupstr