Merging upstream version 1.5~rc1.

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

1 files changed, 36 insertions, 5 deletions

diff --git a/decoder.h b/decoder.h
index 063511b..118fe23 100644
--- a/decoder.h
+++ b/decoder.h
@@ -85,6 +85,7 @@ static inline void Rd_load( struct Range_decoder * const rdec )
   for( i = 0; i < 5; ++i )
     rdec->code = (rdec->code << 8) | Rd_get_byte( rdec );
   rdec->range = 0xFFFFFFFFU;
+  rdec->code &= rdec->range;	/* make sure that first byte is discarded */
   }
 
 static inline void Rd_normalize( struct Range_decoder * const rdec )
@@ -259,6 +260,9 @@ void LZd_flush_data( struct LZ_decoder * const decoder );
 bool LZd_verify_trailer( struct LZ_decoder * const decoder,
                          struct Pretty_print * const pp );
 
+int seek_read( const int fd, uint8_t * const buf, const int size,
+               const int offset );
+
 static inline uint8_t LZd_get_prev_byte( const struct LZ_decoder * const decoder )
   {
   const int i =
@@ -269,9 +273,14 @@ static inline uint8_t LZd_get_prev_byte( const struct LZ_decoder * const decoder
 static inline uint8_t LZd_get_byte( const struct LZ_decoder * const decoder,
                                     const int distance )
   {
-  int i = decoder->pos - distance - 1;
-  if( i < 0 ) i += decoder->buffer_size;
-  return decoder->buffer[i];
+  uint8_t b;
+  const int i = decoder->pos - distance - 1;
+  if( i >= 0 ) b = decoder->buffer[i];
+  else if( i + decoder->buffer_size >= decoder->pos )
+    b = decoder->buffer[i+decoder->buffer_size];
+  else if( seek_read( decoder->outfd, &b, 1, i - decoder->stream_pos ) != 1 )
+    { show_error( "Seek error", errno, false ); cleanup_and_fail( 1 ); }
+  return b;
   }
 
 static inline void LZd_put_byte( struct LZ_decoder * const decoder,
@@ -300,13 +309,35 @@ static inline void LZd_copy_block( struct LZ_decoder * const decoder,
     }
   }
 
+static inline void LZd_copy_block2( struct LZ_decoder * const decoder,
+                                    const int distance, int len )
+  {
+  if( distance < decoder->buffer_size )		/* block is in buffer */
+    { LZd_copy_block( decoder, distance, len ); return; }
+  if( len < decoder->buffer_size - decoder->pos )	/* no wrap */
+    {
+    const int offset = decoder->pos - decoder->stream_pos - distance - 1;
+    if( len <= -offset )			/* block is in file */
+      {
+      if( seek_read( decoder->outfd, decoder->buffer + decoder->pos, len, offset ) != len )
+        { show_error( "Seek error", errno, false ); cleanup_and_fail( 1 ); }
+      decoder->pos += len;
+      return;
+      }
+    }
+  for( ; len > 0; --len )
+    LZd_put_byte( decoder, LZd_get_byte( decoder, distance ) );
+  }
+
 static inline bool LZd_init( struct LZ_decoder * const decoder,
                              const File_header header,
-                             struct Range_decoder * const rde, const int ofd )
+                             struct Range_decoder * const rde,
+                             const int buffer_size, const int ofd )
   {
   decoder->partial_data_pos = 0;
   decoder->dictionary_size = Fh_get_dictionary_size( header );
-  decoder->buffer_size = max( 65536, decoder->dictionary_size );
+  decoder->buffer_size =
+    min( buffer_size, max( 65536, decoder->dictionary_size ) );
   decoder->buffer = (uint8_t *)malloc( decoder->buffer_size );
   if( !decoder->buffer ) return false;
   decoder->pos = 0;