From 583b241cef15e59507a6187bb58a6c38e682402f Mon Sep 17 00:00:00 2001
From: zroug <37004975+zroug@users.noreply.github.com>
Date: Mon, 27 Aug 2018 23:05:16 +0200
Subject: [PATCH 1/3] Replaced unsafe code in Decoder::read_image

---
 src/decoder/mod.rs | 19 +++----------------
 1 file changed, 3 insertions(+), 16 deletions(-)

diff --git a/src/decoder/mod.rs b/src/decoder/mod.rs
index 045944a..2495de4 100644
--- a/src/decoder/mod.rs
+++ b/src/decoder/mod.rs
@@ -467,8 +467,8 @@ impl<R: Read + Seek> Decoder<R> {
             * self.height as usize
             * self.bits_per_sample.iter().count();
         let mut result = match self.bits_per_sample.iter().cloned().max().unwrap_or(8) {
-            n if n <= 8 => DecodingResult::U8(Vec::with_capacity(buffer_size)),
-            n if n <= 16 => DecodingResult::U16(Vec::with_capacity(buffer_size)),
+            n if n <= 8 => DecodingResult::U8(vec![0; buffer_size]),
+            n if n <= 16 => DecodingResult::U16(vec![0; buffer_size]),
             n => return Err(
                 TiffError::UnsupportedError(
                     format!("{} bits per channel not supported", n)
@@ -483,13 +483,6 @@ impl<R: Read + Seek> Decoder<R> {
                 ))
             }
         }
-        // Safe since the uninitialized values are never read.
-        match result {
-            DecodingResult::U8(ref mut buffer) =>
-                unsafe { buffer.set_len(buffer_size) },
-            DecodingResult::U16(ref mut buffer) =>
-                unsafe { buffer.set_len(buffer_size) },
-        }
         let mut units_read = 0;
         for (i, (&offset, &byte_count)) in try!(self.get_tag_u32_vec(ifd::Tag::StripOffsets))
         .iter().zip(try!(self.get_tag_u32_vec(ifd::Tag::StripByteCounts)).iter()).enumerate() {
@@ -514,14 +507,8 @@ impl<R: Read + Seek> Decoder<R> {
                 break
             }
         }
-        // Shrink length such that the uninitialized memory is not exposed.
         if units_read < buffer_size {
-            match result {
-                DecodingResult::U8(ref mut buffer) =>
-                    unsafe { buffer.set_len(units_read) },
-                DecodingResult::U16(ref mut buffer) =>
-                    unsafe { buffer.set_len(units_read) },
-            }
+            return Err(TiffError::FormatError("Inconsistent sizes encountered.".to_string()));
         }
         if let Ok(predictor) = self.get_tag_u32(ifd::Tag::Predictor) {
             result = match FromPrimitive::from_u32(predictor) {

From 724e5e8c801ce82f4189414f9371f9f70267c99c Mon Sep 17 00:00:00 2001
From: zroug <37004975+zroug@users.noreply.github.com>
Date: Mon, 27 Aug 2018 23:05:16 +0200
Subject: [PATCH 2/3] Fixed: Decoder::expand_strip might not read the full
 strip

---
 src/decoder/mod.rs | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/decoder/mod.rs b/src/decoder/mod.rs
index 2495de4..2c7bdcd 100644
--- a/src/decoder/mod.rs
+++ b/src/decoder/mod.rs
@@ -422,7 +422,8 @@ impl<R: Read + Seek> Decoder<R> {
             (ColorType:: RGB(8), DecodingBuffer::U8(ref mut buffer)) |
             (ColorType::RGBA(8), DecodingBuffer::U8(ref mut buffer)) | 
             (ColorType::CMYK(8), DecodingBuffer::U8(ref mut buffer)) => {
-                try!(reader.read(&mut buffer[..bytes]))
+                try!(reader.read_exact(&mut buffer[..bytes]));
+                bytes
             }
             (ColorType::RGBA(16), DecodingBuffer::U16(ref mut buffer)) |
             (ColorType:: RGB(16), DecodingBuffer::U16(ref mut buffer)) => {

From 345aff0629117ca4dae318157d530b3fd878e793 Mon Sep 17 00:00:00 2001
From: zroug <37004975+zroug@users.noreply.github.com>
Date: Mon, 27 Aug 2018 23:05:16 +0200
Subject: [PATCH 3/3] Greatly improved performance for 16 bit images

---
 src/decoder/mod.rs    | 10 ++++------
 src/decoder/stream.rs |  8 ++++++++
 2 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/src/decoder/mod.rs b/src/decoder/mod.rs
index 2c7bdcd..48580b4 100644
--- a/src/decoder/mod.rs
+++ b/src/decoder/mod.rs
@@ -427,15 +427,13 @@ impl<R: Read + Seek> Decoder<R> {
             }
             (ColorType::RGBA(16), DecodingBuffer::U16(ref mut buffer)) |
             (ColorType:: RGB(16), DecodingBuffer::U16(ref mut buffer)) => {
-                for datum in buffer[..bytes/2].iter_mut() {
-                    *datum = try!(reader.read_u16())
-                }
+                try!(reader.read_u16_into(&mut buffer[..bytes/2]));
                 bytes/2
             }
             (ColorType::Gray(16), DecodingBuffer::U16(ref mut buffer)) => {
-                for datum in buffer[..bytes/2].iter_mut() {
-                    *datum = try!(reader.read_u16());
-                    if self.photometric_interpretation == PhotometricInterpretation::WhiteIsZero {
+                try!(reader.read_u16_into(&mut buffer[..bytes/2]));
+                if self.photometric_interpretation == PhotometricInterpretation::WhiteIsZero {
+                    for datum in buffer[..bytes/2].iter_mut() {
                         *datum = 0xffff - *datum
                     }
                 }
diff --git a/src/decoder/stream.rs b/src/decoder/stream.rs
index 090a833..c80b84e 100644
--- a/src/decoder/stream.rs
+++ b/src/decoder/stream.rs
@@ -28,6 +28,14 @@ pub trait EndianReader: Read {
         }
     }
 
+    #[inline(always)]
+    fn read_u16_into(&mut self, buffer: &mut [u16]) -> Result<(), io::Error> {
+        match self.byte_order() {
+            ByteOrder::LittleEndian => <Self as ReadBytesExt>::read_u16_into::<LittleEndian>(self, buffer),
+            ByteOrder::BigEndian => <Self as ReadBytesExt>::read_u16_into::<BigEndian>(self, buffer)
+        }
+    }
+
     /// Reads an u32
     #[inline(always)]
     fn read_u32(&mut self) -> Result<u32, io::Error> {