Upstream version 7.36.149.0

[platform/framework/web/crosswalk.git] / src / third_party / libwebp / utils / bit_reader.c

diff --git a/src/third_party/libwebp/utils/bit_reader.c b/src/third_party/libwebp/utils/bit_reader.c
index bfa4d7d..79f64d3 100644 (file)
--- a/src/third_party/libwebp/utils/bit_reader.c
+++ b/src/third_party/libwebp/utils/bit_reader.c
@@ -141,14 +141,24 @@ void VP8LInitBitReader(VP8LBitReader* const br,
   }
 }
 
+// Special version that assumes br->pos_ <= br_len_.
+static int IsEndOfStreamSpecial(const VP8LBitReader* const br) {
+  assert(br->pos_ <= br->len_);
+  return br->pos_ == br->len_ && br->bit_pos_ >= LBITS;
+}
+
+static int IsEndOfStream(const VP8LBitReader* const br) {
+  return (br->pos_ > br->len_) || IsEndOfStreamSpecial(br);
+}
+
 void VP8LBitReaderSetBuffer(VP8LBitReader* const br,
                             const uint8_t* const buf, size_t len) {
   assert(br != NULL);
   assert(buf != NULL);
   assert(len < 0xfffffff8u);   // can't happen with a RIFF chunk.
-  br->eos_ = (br->pos_ >= len);
   br->buf_ = buf;
   br->len_ = len;
+  br->eos_ = IsEndOfStream(br);
 }
 
 // If not at EOS, reload up to LBITS byte-by-byte
@@ -175,9 +185,7 @@ void VP8LFillBitWindow(VP8LBitReader* const br) {
     }
 #endif
     ShiftBytes(br);       // Slow path.
-    if (br->pos_ == br->len_ && br->bit_pos_ >= LBITS) {
-      br->eos_ = 1;
-    }
+    br->eos_ = IsEndOfStreamSpecial(br);
   }
 }
 
@@ -190,11 +198,7 @@ uint32_t VP8LReadBits(VP8LBitReader* const br, int n_bits) {
     const int new_bits = br->bit_pos_ + n_bits;
     br->bit_pos_ = new_bits;
     // If this read is going to cross the read buffer, set the eos flag.
-    if (br->pos_ == br->len_) {
-      if (new_bits >= LBITS) {
-        br->eos_ = 1;
-      }
-    }
+    br->eos_ = IsEndOfStreamSpecial(br);
     ShiftBytes(br);
     return val;
   } else {