From f2d3e8c3c5a4197040e87d69b5693efadecc0015 Mon Sep 17 00:00:00 2001
From: Matt Bilker <me@mbilker.us>
Date: Tue, 10 Jul 2018 15:48:28 +0000
Subject: [PATCH] de(seq): require size for sequence

---
 src/de/mod.rs | 6 ++++--
 src/de/seq.rs | 7 +++++--
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/src/de/mod.rs b/src/de/mod.rs
index 449ad91..37facc3 100644
--- a/src/de/mod.rs
+++ b/src/de/mod.rs
@@ -244,10 +244,12 @@ impl<'de, 'a> de::Deserializer<'de> for &'a mut Deserializer<'de> {
     let size = self.data_buf.read_u32::<BigEndian>().context(KbinErrorKind::ArrayLengthRead)?;
     debug!("Deserializer::deserialize_seq() => read array size: {}", size);
 
+    // Changes to `self.read_mode` must stay here as `next_element_seed` is not
+    // called past the length of the array to reset the read mode
     self.read_mode = ReadMode::Array;
-    let value = visitor.visit_seq(Seq::new(self, Some(size as usize)))?;
-    self.data_buf.realign_reads(None)?;
+    let value = visitor.visit_seq(Seq::new(self, size as usize))?;
     self.read_mode = ReadMode::Single;
+    self.data_buf.realign_reads(None)?;
 
     Ok(value)
   }
diff --git a/src/de/seq.rs b/src/de/seq.rs
index 0c0ee6a..c1e2f71 100644
--- a/src/de/seq.rs
+++ b/src/de/seq.rs
@@ -10,8 +10,9 @@ pub struct Seq<'a, 'de: 'a> {
 }
 
 impl<'de, 'a> Seq<'a, 'de> {
-  pub fn new(de: &'a mut Deserializer<'de>, len: Option<usize>) -> Self {
-    let len = len.unwrap_or(0);
+  pub fn new(de: &'a mut Deserializer<'de>, len: usize) -> Self {
+    trace!("Seq::new(len: {})", len);
+
     Self {
       de,
       index: 0,
@@ -27,6 +28,8 @@ impl<'de, 'a> SeqAccess<'de> for Seq<'a, 'de> {
     where T: DeserializeSeed<'de>
   {
     if self.index >= self.len {
+      trace!("Seq::next_element_seed() => out of bounds read, returning None");
+
       return Ok(None);
     }
     self.index += 1;