nihav_core/deflate: recognize deflated stream header in uncompress()

[nihav.git] / nihav-core / src / compr / deflate.rs

diff --git a/nihav-core/src/compr/deflate.rs b/nihav-core/src/compr/deflate.rs
index 1b3dc68290ccdde1977025d9e2623c21abf9109a..fa318a473e84647e9ca281cfa6fc868c243c812a 100644 (file)
--- 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);
@@ -355,7 +356,7 @@ impl Inflate {
     ///! [`DecompressError::ShortData`]: ../enum.DecompressError.html#variant.ShortData
     ///! [`DecompressError::OutputFull`]: ../enum.DecompressError.html#variant.OutputFull
     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 +598,15 @@ 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 +716,14 @@ 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()
     }
 }
 
@@ -757,6 +764,7 @@ struct GzipCRC32 {
 }
 
 impl GzipCRC32 {
+    #[allow(clippy::unreadable_literal)]
     fn new() -> Self {
         let mut tab = [0u32; 256];
         for i in 0..256 {