Merging upstream version 1.8.

Signed-off-by: Daniel Baumann <mail@daniel-baumann.ch>

1 files changed, 42 insertions, 29 deletions

diff --git a/cbuffer.c b/cbuffer.c
index a97c08e..89693ab 100644
--- a/cbuffer.c
+++ b/cbuffer.c
@@ -1,5 +1,5 @@
 /*  Lzlib - Compression library for the lzip format
-    Copyright (C) 2009-2015 Antonio Diaz Diaz.
+    Copyright (C) 2009-2016 Antonio Diaz Diaz.
 
     This library is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -28,56 +28,68 @@
 struct Circular_buffer
   {
   uint8_t * buffer;
-  int buffer_size;		/* capacity == buffer_size - 1 */
-  int get;			/* buffer is empty when get == put */
-  int put;
+  unsigned buffer_size;		/* capacity == buffer_size - 1 */
+  unsigned get;			/* buffer is empty when get == put */
+  unsigned put;
   };
 
 static inline void Cb_reset( struct Circular_buffer * const cb )
   { cb->get = 0; cb->put = 0; }
 
 static inline bool Cb_init( struct Circular_buffer * const cb,
-                            const int buf_size )
+                            const unsigned buf_size )
   {
-  cb->buffer = (uint8_t *)malloc( buf_size + 1 );
   cb->buffer_size = buf_size + 1;
   cb->get = 0;
   cb->put = 0;
+  cb->buffer =
+    ( cb->buffer_size > 1 ) ? (uint8_t *)malloc( cb->buffer_size ) : 0;
   return ( cb->buffer != 0 );
   }
 
 static inline void Cb_free( struct Circular_buffer * const cb )
   { free( cb->buffer ); cb->buffer = 0; }
 
-static inline int Cb_used_bytes( const struct Circular_buffer * const cb )
-    { return ( (cb->get <= cb->put) ? 0 : cb->buffer_size ) + cb->put - cb->get; }
+static inline unsigned Cb_used_bytes( const struct Circular_buffer * const cb )
+  { return ( (cb->get <= cb->put) ? 0 : cb->buffer_size ) + cb->put - cb->get; }
 
-static inline int Cb_free_bytes( const struct Circular_buffer * const cb )
-    { return ( (cb->get <= cb->put) ? cb->buffer_size : 0 ) - cb->put + cb->get - 1; }
+static inline unsigned Cb_free_bytes( const struct Circular_buffer * const cb )
+  { return ( (cb->get <= cb->put) ? cb->buffer_size : 0 ) - cb->put + cb->get - 1; }
 
 static inline uint8_t Cb_get_byte( struct Circular_buffer * const cb )
-    {
-    const uint8_t b = cb->buffer[cb->get];
-    if( ++cb->get >= cb->buffer_size ) cb->get = 0;
-    return b;
-    }
+  {
+  const uint8_t b = cb->buffer[cb->get];
+  if( ++cb->get >= cb->buffer_size ) cb->get = 0;
+  return b;
+  }
 
 static inline void Cb_put_byte( struct Circular_buffer * const cb,
                                 const uint8_t b )
-    {
-    cb->buffer[cb->put] = b;
-    if( ++cb->put >= cb->buffer_size ) cb->put = 0;
-    }
+  {
+  cb->buffer[cb->put] = b;
+  if( ++cb->put >= cb->buffer_size ) cb->put = 0;
+  }
+
+
+static bool Cb_unread_data( struct Circular_buffer * const cb,
+                            const unsigned size )
+  {
+  if( size > Cb_free_bytes( cb ) ) return false;
+  if( cb->get >= size ) cb->get -= size;
+  else cb->get = cb->buffer_size - size + cb->get;
+  return true;
+  }
 
 
 /* Copies up to 'out_size' bytes to 'out_buffer' and updates 'get'.
    Returns the number of bytes copied.
 */
-static int Cb_read_data( struct Circular_buffer * const cb,
-                         uint8_t * const out_buffer, const int out_size )
+static unsigned Cb_read_data( struct Circular_buffer * const cb,
+                              uint8_t * const out_buffer,
+                              const unsigned out_size )
   {
-  int size = 0;
-  if( out_size <= 0 ) return 0;
+  unsigned size = 0;
+  if( out_size == 0 ) return 0;
   if( cb->get > cb->put )
     {
     size = min( cb->buffer_size - cb->get, out_size );
@@ -90,7 +102,7 @@ static int Cb_read_data( struct Circular_buffer * const cb,
     }
   if( cb->get < cb->put )
     {
-    const int size2 = min( cb->put - cb->get, out_size - size );
+    const unsigned size2 = min( cb->put - cb->get, out_size - size );
     if( size2 > 0 )
       {
       memcpy( out_buffer + size, cb->buffer + cb->get, size2 );
@@ -105,11 +117,12 @@ static int Cb_read_data( struct Circular_buffer * const cb,
 /* Copies up to 'in_size' bytes from 'in_buffer' and updates 'put'.
    Returns the number of bytes copied.
 */
-static int Cb_write_data( struct Circular_buffer * const cb,
-                          const uint8_t * const in_buffer, const int in_size )
+static unsigned Cb_write_data( struct Circular_buffer * const cb,
+                               const uint8_t * const in_buffer,
+                               const unsigned in_size )
   {
-  int size = 0;
-  if( in_size < 0 ) return 0;
+  unsigned size = 0;
+  if( in_size == 0 ) return 0;
   if( cb->put >= cb->get )
     {
     size = min( cb->buffer_size - cb->put - (cb->get == 0), in_size );
@@ -122,7 +135,7 @@ static int Cb_write_data( struct Circular_buffer * const cb,
     }
   if( cb->put < cb->get )
     {
-    const int size2 = min( cb->get - cb->put - 1, in_size - size );
+    const unsigned size2 = min( cb->get - cb->put - 1, in_size - size );
     if( size2 > 0 )
       {
       memcpy( cb->buffer + cb->put, in_buffer + size, size2 );