From b114e552211456fbde3ff6ca2da21cbc8d1e90e2 Mon Sep 17 00:00:00 2001
From: Liang Qi <liang.qi@theqtcompany.com>
Date: Wed, 9 Mar 2016 10:22:13 +0100
Subject: libwebp: update to 0.5.0

This commit imports libwebp 0.5.0, including AUTHORS, COPYING, ChangeLog,
NEWS, PATENTS, README and src directories. In src, only includes header
and source files.

The patches required to build it in Qt will follow in separate
commit(s).

Change-Id: I96b4961ba63c75cc7fbab158c36a0f403f254c14
Reviewed-by: aavit <eirik.aavitsland@theqtcompany.com>
---
 src/3rdparty/libwebp/src/utils/bit_reader.c | 42 ++++++++++++++++++++---------
 1 file changed, 29 insertions(+), 13 deletions(-)

(limited to 'src/3rdparty/libwebp/src/utils/bit_reader.c')

diff --git a/src/3rdparty/libwebp/src/utils/bit_reader.c b/src/3rdparty/libwebp/src/utils/bit_reader.c
index 64503e6..45198e1 100644
--- a/src/3rdparty/libwebp/src/utils/bit_reader.c
+++ b/src/3rdparty/libwebp/src/utils/bit_reader.c
@@ -20,17 +20,26 @@
 //------------------------------------------------------------------------------
 // VP8BitReader
 
+void VP8BitReaderSetBuffer(VP8BitReader* const br,
+                           const uint8_t* const start,
+                           size_t size) {
+  br->buf_     = start;
+  br->buf_end_ = start + size;
+  br->buf_max_ =
+      (size >= sizeof(lbit_t)) ? start + size - sizeof(lbit_t) + 1
+                               : start;
+}
+
 void VP8InitBitReader(VP8BitReader* const br,
-                      const uint8_t* const start, const uint8_t* const end) {
+                      const uint8_t* const start, size_t size) {
   assert(br != NULL);
   assert(start != NULL);
-  assert(start <= end);
+  assert(size < (1u << 31));   // limit ensured by format and upstream checks
   br->range_   = 255 - 1;
-  br->buf_     = start;
-  br->buf_end_ = end;
   br->value_   = 0;
   br->bits_    = -8;   // to load the very first 8bits
   br->eof_     = 0;
+  VP8BitReaderSetBuffer(br, start, size);
   VP8LoadNewBytes(br);
 }
 
@@ -38,6 +47,7 @@ void VP8RemapBitReader(VP8BitReader* const br, ptrdiff_t offset) {
   if (br->buf_ != NULL) {
     br->buf_ += offset;
     br->buf_end_ += offset;
+    br->buf_max_ += offset;
   }
 }
 
@@ -54,7 +64,7 @@ const uint8_t kVP8Log2Range[128] = {
 };
 
 // range = ((range - 1) << kVP8Log2Range[range]) + 1
-const range_t kVP8NewRange[128] = {
+const uint8_t kVP8NewRange[128] = {
   127, 127, 191, 127, 159, 191, 223, 127,
   143, 159, 175, 191, 207, 223, 239, 127,
   135, 143, 151, 159, 167, 175, 183, 191,
@@ -83,6 +93,8 @@ void VP8LoadFinalBytes(VP8BitReader* const br) {
     br->value_ <<= 8;
     br->bits_ += 8;
     br->eof_ = 1;
+  } else {
+    br->bits_ = 0;  // This is to avoid undefined behaviour with shifts.
   }
 }
 
@@ -136,7 +148,6 @@ void VP8LInitBitReader(VP8LBitReader* const br, const uint8_t* const start,
   br->val_ = 0;
   br->bit_pos_ = 0;
   br->eos_ = 0;
-  br->error_ = 0;
 
   if (length > sizeof(br->val_)) {
     length = sizeof(br->val_);
@@ -157,8 +168,12 @@ void VP8LBitReaderSetBuffer(VP8LBitReader* const br,
   br->buf_ = buf;
   br->len_ = len;
   // pos_ > len_ should be considered a param error.
-  br->error_ = (br->pos_ > br->len_);
-  br->eos_ = br->error_ || VP8LIsEndOfStream(br);
+  br->eos_ = (br->pos_ > br->len_) || VP8LIsEndOfStream(br);
+}
+
+static void VP8LSetEndOfStream(VP8LBitReader* const br) {
+  br->eos_ = 1;
+  br->bit_pos_ = 0;  // To avoid undefined behaviour with shifts.
 }
 
 // If not at EOS, reload up to VP8L_LBITS byte-by-byte
@@ -169,7 +184,9 @@ static void ShiftBytes(VP8LBitReader* const br) {
     ++br->pos_;
     br->bit_pos_ -= 8;
   }
-  br->eos_ = VP8LIsEndOfStream(br);
+  if (VP8LIsEndOfStream(br)) {
+    VP8LSetEndOfStream(br);
+  }
 }
 
 void VP8LDoFillBitWindow(VP8LBitReader* const br) {
@@ -182,7 +199,7 @@ void VP8LDoFillBitWindow(VP8LBitReader* const br) {
     br->bit_pos_ -= VP8L_WBITS;
     // The expression below needs a little-endian arch to work correctly.
     // This gives a large speedup for decoding speed.
-    br->val_ |= (vp8l_val_t)*(const uint32_t*)(br->buf_ + br->pos_) <<
+    br->val_ |= (vp8l_val_t)WebPMemToUint32(br->buf_ + br->pos_) <<
                 (VP8L_LBITS - VP8L_WBITS);
     br->pos_ += VP8L_LOG8_WBITS;
     return;
@@ -195,14 +212,13 @@ uint32_t VP8LReadBits(VP8LBitReader* const br, int n_bits) {
   assert(n_bits >= 0);
   // Flag an error if end_of_stream or n_bits is more than allowed limit.
   if (!br->eos_ && n_bits <= VP8L_MAX_NUM_BIT_READ) {
-    const uint32_t val =
-        (uint32_t)(br->val_ >> br->bit_pos_) & kBitMask[n_bits];
+    const uint32_t val = VP8LPrefetchBits(br) & kBitMask[n_bits];
     const int new_bits = br->bit_pos_ + n_bits;
     br->bit_pos_ = new_bits;
     ShiftBytes(br);
     return val;
   } else {
-    br->error_ = 1;
+    VP8LSetEndOfStream(br);
     return 0;
   }
 }
-- 
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