From 08d74977062ad221452ddb368ac842fa065d70e8 Mon Sep 17 00:00:00 2001
From: Tpt <thomas@pellissier-tanon.fr>
Date: Wed, 6 Jun 2018 13:29:53 +0200
Subject: [PATCH] Adds proper escaping of string literals

---
 src/lib.rs        |  1 +
 src/model/data.rs |  7 +++--
 src/utils.rs      | 73 +++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 78 insertions(+), 3 deletions(-)
 create mode 100644 src/utils.rs

diff --git a/src/lib.rs b/src/lib.rs
index 1777b8b6..586d4b87 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -6,3 +6,4 @@ extern crate uuid;
 pub mod model;
 pub mod rio;
 pub mod store;
+mod utils;
diff --git a/src/model/data.rs b/src/model/data.rs
index 854d1ca2..8eb7434f 100644
--- a/src/model/data.rs
+++ b/src/model/data.rs
@@ -7,6 +7,7 @@ use std::str::FromStr;
 use std::sync::Arc;
 use url::ParseError;
 use url::Url;
+use utils::Escaper;
 use uuid::Uuid;
 
 /// A RDF [IRI](https://www.w3.org/TR/rdf11-concepts/#dfn-iri)
@@ -163,10 +164,10 @@ impl fmt::Display for Literal {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         if self.is_plain() {
             self.language()
-                .map(|lang| write!(f, "\"{}\"@{}", self.value(), lang))
-                .unwrap_or_else(|| write!(f, "\"{}\"", self.value()))
+                .map(|lang| write!(f, "\"{}\"@{}", self.value().escape(), lang))
+                .unwrap_or_else(|| write!(f, "\"{}\"", self.value().escape()))
         } else {
-            write!(f, "\"{}\"^^{}", self.value(), self.datatype())
+            write!(f, "\"{}\"^^{}", self.value().escape(), self.datatype())
         }
     }
 }
diff --git a/src/utils.rs b/src/utils.rs
new file mode 100644
index 00000000..eb0960b5
--- /dev/null
+++ b/src/utils.rs
@@ -0,0 +1,73 @@
+pub trait Escaper {
+    fn escape(&self) -> String;
+}
+
+impl<'a> Escaper for &'a str {
+    fn escape(&self) -> String {
+        self.chars().flat_map(|c| EscapeRDF::new(c)).collect()
+    }
+}
+
+/// Customized version of EscapeDefault of the Rust standard library
+struct EscapeRDF {
+    state: EscapeRdfState,
+}
+
+enum EscapeRdfState {
+    Done,
+    Char(char),
+    Backslash(char),
+}
+
+impl EscapeRDF {
+    fn new(c: char) -> EscapeRDF {
+        EscapeRDF {
+            state: match c {
+                '\t' => EscapeRdfState::Backslash('t'),
+                '\u{08}' => EscapeRdfState::Backslash('b'),
+                '\n' => EscapeRdfState::Backslash('n'),
+                '\r' => EscapeRdfState::Backslash('r'),
+                '\u{0C}' => EscapeRdfState::Backslash('f'),
+                '\\' | '\'' | '"' => EscapeRdfState::Backslash(c),
+                c => EscapeRdfState::Char(c),
+            },
+        }
+    }
+}
+
+impl Iterator for EscapeRDF {
+    type Item = char;
+
+    fn next(&mut self) -> Option<char> {
+        match self.state {
+            EscapeRdfState::Backslash(c) => {
+                self.state = EscapeRdfState::Char(c);
+                Some('\\')
+            }
+            EscapeRdfState::Char(c) => {
+                self.state = EscapeRdfState::Done;
+                Some(c)
+            }
+            EscapeRdfState::Done => None,
+        }
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        let n = self.len();
+        (n, Some(n))
+    }
+
+    fn count(self) -> usize {
+        self.len()
+    }
+}
+
+impl ExactSizeIterator for EscapeRDF {
+    fn len(&self) -> usize {
+        match self.state {
+            EscapeRdfState::Done => 0,
+            EscapeRdfState::Char(_) => 1,
+            EscapeRdfState::Backslash(_) => 2,
+        }
+    }
+}