X-Git-Url: https://git.nihav.org/?p=nihav.git;a=blobdiff_plain;f=nihav-core%2Fsrc%2Fcompr%2Fdeflate.rs;h=3462a4034996445255b9ad0f93f79671fae12e9e;hp=8e91caa369789267c4dec7d08468cf50f244dbd6;hb=b7c882c1ce6f86c07c2340751200e3a060942826;hpb=0443d0c5f73697d5eb59081be3cde9fb02dc3e70

diff --git a/nihav-core/src/compr/deflate.rs b/nihav-core/src/compr/deflate.rs
index 8e91caa..3462a40 100644
--- a/nihav-core/src/compr/deflate.rs
+++ b/nihav-core/src/compr/deflate.rs
@@ -72,6 +72,7 @@ impl CodebookDescReader<u16> for FixedLenCodeReader {
         else if idx < 280 { 7 }
         else              { 8 }
     }
+    #[allow(clippy::identity_op)]
     fn code(&mut self, idx: usize) -> u32 {
         let base = idx as u32;
         let bits = self.bits(idx);
@@ -226,6 +227,7 @@ pub struct Inflate {
     buf:            [u8; 65536],
     bpos:           usize,
     output_idx:     usize,
+    full_pos:       usize,
 
     state:          InflateState,
     final_block:    bool,
@@ -304,6 +306,7 @@ impl Inflate {
             buf:            [0; 65536],
             bpos:           0,
             output_idx:     0,
+            full_pos:       0,
 
             state:          InflateState::Start,
             final_block:    false,
@@ -319,19 +322,21 @@ impl Inflate {
     }
     fn put_literal(&mut self, val: u8) {
         self.buf[self.bpos] = val;
-        self.bpos += 1;
+        self.bpos = (self.bpos + 1) & (self.buf.len() - 1);
+        self.full_pos += 1;
     }
     fn lz_copy(&mut self, offset: usize, len: usize, dst: &mut [u8]) -> DecompressResult<()> {
         let mask = self.buf.len() - 1;
-        if self.bpos < offset {
+        if offset > self.full_pos {
             return Err(DecompressError::InvalidData);
         }
-        let cstart = (self.bpos - offset) & mask;
+        let cstart = (self.bpos.wrapping_sub(offset)) & mask;
         for i in 0..len {
             self.buf[(self.bpos + i) & mask] = self.buf[(cstart + i) & mask];
             dst[i] = self.buf[(cstart + i) & mask];
         }
-        self.bpos += len;
+        self.bpos = (self.bpos + len) & mask;
+        self.full_pos += len;
         Ok(())
     }
     ///! Reports whether decoder has finished decoding the input.
@@ -354,8 +359,9 @@ impl Inflate {
     ///!
     ///! [`DecompressError::ShortData`]: ../enum.DecompressError.html#variant.ShortData
     ///! [`DecompressError::OutputFull`]: ../enum.DecompressError.html#variant.OutputFull
+    #[allow(clippy::comparison_chain)]
     pub fn decompress_data(&mut self, src: &[u8], dst: &mut [u8], continue_block: bool) -> DecompressResult<usize> {
-        if src.len() == 0 || dst.len() == 0 {
+        if src.is_empty() || dst.is_empty() {
             return Err(DecompressError::InvalidArgument);
         }
         let mut csrc = if !continue_block {
@@ -597,16 +603,15 @@ impl Inflate {
                         self.state = InflateState::End;
                         return Err(DecompressError::InvalidHeader);
                     }
-                    let rpt;
-                    if mode == 0 {
-                        if self.cur_len_idx == 0 {
-                            self.state = InflateState::End;
-                            return Err(DecompressError::InvalidHeader);
-                        }
-                        rpt = self.all_lengths[self.cur_len_idx - 1];
-                    } else {
-                        rpt = 0;
-                    }
+                    let rpt = if mode == 0 {
+                            if self.cur_len_idx == 0 {
+                                self.state = InflateState::End;
+                                return Err(DecompressError::InvalidHeader);
+                            }
+                            self.all_lengths[self.cur_len_idx - 1]
+                        } else {
+                            0
+                        };
                     for _ in 0..len {
                         self.all_lengths[self.cur_len_idx] = rpt;
                         self.cur_len_idx += 1;
@@ -716,7 +721,14 @@ impl Inflate {
     ///! Decompresses input data into output returning the uncompressed data length.
     pub fn uncompress(src: &[u8], dst: &mut [u8]) -> DecompressResult<usize> {
         let mut inflate = Self::new();
-        inflate.decompress_data(src, dst, false)
+        let off = if src.len() > 2 && src[0] == 0x78 && src[1] == 0x9C { 2 } else { 0 };
+        inflate.decompress_data(&src[off..], dst, false)
+    }
+}
+
+impl Default for Inflate {
+    fn default() -> Self {
+        Self::new()
     }
 }
 
@@ -747,7 +759,7 @@ fn lengths_to_codes(lens: &[u8], codes: &mut [ShortCodebookDesc]) -> DecompressR
             *codes = ShortCodebookDesc { code: 0, bits: 0 };
         }
     }
-    
+
     Ok(())
 }
 
@@ -757,6 +769,7 @@ struct GzipCRC32 {
 }
 
 impl GzipCRC32 {
+    #[allow(clippy::unreadable_literal)]
     fn new() -> Self {
         let mut tab = [0u32; 256];
         for i in 0..256 {