From e995433296c7e7d1e6c3269902d3bf0f4fcdd602 Mon Sep 17 00:00:00 2001
From: Jasper Bryant-Greene <jbg@rf.net.nz>
Date: Thu, 19 Sep 2019 16:18:04 +0900
Subject: [PATCH] Remove usage of smallvec due to safety concerns

---
 Cargo.toml       |  1 -
 src/decompose.rs | 15 ++++-----------
 src/lib.rs       |  2 --
 src/recompose.rs |  7 +++----
 4 files changed, 7 insertions(+), 18 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index e4727c7..db77bfe 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -21,4 +21,3 @@ Unicode Standard Annex #15.
 exclude = [ "target/*", "Cargo.lock", "scripts/tmp", "*.txt", "src/normalization_tests.rs", "src/test.rs" ]
 
 [dependencies]
-smallvec = "0.6"
\ No newline at end of file
diff --git a/src/decompose.rs b/src/decompose.rs
index b4ef386..66560bd 100644
--- a/src/decompose.rs
+++ b/src/decompose.rs
@@ -7,7 +7,6 @@
 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
-use smallvec::SmallVec;
 use std::fmt::{self, Write};
 use std::iter::Fuse;
 use std::ops::Range;
@@ -32,7 +31,7 @@ pub struct Decompositions<I> {
     // 2) "Ready" characters which are sorted and ready to emit on demand;
     // 3) A "pending" block which stills needs more characters for us to be able
     //    to sort in canonical order and is not safe to emit.
-    buffer: SmallVec<[(u8, char); 4]>,
+    buffer: Vec<(u8, char)>,
     ready: Range<usize>,
 }
 
@@ -41,7 +40,7 @@ pub fn new_canonical<I: Iterator<Item=char>>(iter: I) -> Decompositions<I> {
     Decompositions {
         kind: self::DecompositionType::Canonical,
         iter: iter.fuse(),
-        buffer: SmallVec::new(),
+        buffer: Vec::with_capacity(4),
         ready: 0..0,
     }
 }
@@ -51,7 +50,7 @@ pub fn new_compatible<I: Iterator<Item=char>>(iter: I) -> Decompositions<I> {
     Decompositions {
         kind: self::DecompositionType::Compatible,
         iter: iter.fuse(),
-        buffer: SmallVec::new(),
+        buffer: Vec::with_capacity(4),
         ready: 0..0,
     }
 }
@@ -78,13 +77,7 @@ impl<I> Decompositions<I> {
 
     #[inline]
     fn reset_buffer(&mut self) {
-        // Equivalent to `self.buffer.drain(0..self.ready.end)` (if SmallVec
-        // supported this API)
-        let pending = self.buffer.len() - self.ready.end;
-        for i in 0..pending {
-            self.buffer[i] = self.buffer[i + self.ready.end];
-        }
-        self.buffer.truncate(pending);
+        let _ = self.buffer.drain(0..self.ready.end).count();
         self.ready = 0..0;
     }
 
diff --git a/src/lib.rs b/src/lib.rs
index 7a4b4e0..8ddb95d 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -41,8 +41,6 @@
 #![doc(html_logo_url = "https://unicode-rs.github.io/unicode-rs_sm.png",
        html_favicon_url = "https://unicode-rs.github.io/unicode-rs_sm.png")]
 
-extern crate smallvec;
-
 pub use tables::UNICODE_VERSION;
 pub use decompose::Decompositions;
 pub use quick_check::{
diff --git a/src/recompose.rs b/src/recompose.rs
index 4c2bf97..04e862c 100644
--- a/src/recompose.rs
+++ b/src/recompose.rs
@@ -9,7 +9,6 @@
 // except according to those terms.
 
 use decompose::Decompositions;
-use smallvec::SmallVec;
 use std::fmt::{self, Write};
 
 #[derive(Clone)]
@@ -24,7 +23,7 @@ enum RecompositionState {
 pub struct Recompositions<I> {
     iter: Decompositions<I>,
     state: RecompositionState,
-    buffer: SmallVec<[char; 4]>,
+    buffer: Vec<char>,
     composee: Option<char>,
     last_ccc: Option<u8>,
 }
@@ -34,7 +33,7 @@ pub fn new_canonical<I: Iterator<Item=char>>(iter: I) -> Recompositions<I> {
     Recompositions {
         iter: super::decompose::new_canonical(iter),
         state: self::RecompositionState::Composing,
-        buffer: SmallVec::new(),
+        buffer: Vec::with_capacity(4),
         composee: None,
         last_ccc: None,
     }
@@ -45,7 +44,7 @@ pub fn new_compatible<I: Iterator<Item=char>>(iter: I) -> Recompositions<I> {
     Recompositions {
         iter: super::decompose::new_compatible(iter),
         state: self::RecompositionState::Composing,
-        buffer: SmallVec::new(),
+        buffer: Vec::with_capacity(4),
         composee: None,
         last_ccc: None,
     }