From bf37d7c6771b237537a01aa19c9fe032a2e0657b Mon Sep 17 00:00:00 2001
From: Tpt <thomas@pellissier-tanon.fr>
Date: Thu, 21 Feb 2019 15:26:18 +0100
Subject: [PATCH] Fixes langMatches evaluation

---
 lib/Cargo.toml                 |  1 -
 lib/src/sparql/eval.rs         | 38 +++++++++++++++++++++++++++++-----
 lib/tests/sparql_test_cases.rs |  7 -------
 3 files changed, 33 insertions(+), 13 deletions(-)

diff --git a/lib/Cargo.toml b/lib/Cargo.toml
index fcf8c038..008128f3 100644
--- a/lib/Cargo.toml
+++ b/lib/Cargo.toml
@@ -27,7 +27,6 @@ ordered-float = "1"
 num-traits = "0.2"
 rust_decimal = "0.11"
 chrono = "0.4"
-language-tags = "0.2"
 failure = "0.1"
 regex = "1"
 
diff --git a/lib/src/sparql/eval.rs b/lib/src/sparql/eval.rs
index 1e412c2b..6480e162 100644
--- a/lib/src/sparql/eval.rs
+++ b/lib/src/sparql/eval.rs
@@ -6,7 +6,6 @@ use crate::store::encoded::EncodedQuadsStore;
 use crate::store::numeric_encoder::*;
 use crate::Result;
 use chrono::prelude::*;
-use language_tags::LanguageTag;
 use num_traits::identities::Zero;
 use num_traits::FromPrimitive;
 use num_traits::One;
@@ -19,7 +18,6 @@ use std::collections::BTreeMap;
 use std::collections::HashSet;
 use std::iter::once;
 use std::iter::Iterator;
-use std::str::FromStr;
 use std::sync::Arc;
 use std::sync::Mutex;
 use uuid::Uuid;
@@ -583,9 +581,15 @@ impl<S: EncodedQuadsStore> SimpleEvaluator<S> {
                     if language_range == "*" {
                         !language_tag.is_empty()
                     } else {
-                        LanguageTag::from_str(&language_range)
-                            .ok()?
-                            .matches(&LanguageTag::from_str(&language_tag).ok()?)
+                        !ZipLongest::new(language_range.split('-'), language_tag.split('-')).any(
+                            |parts| match parts {
+                                (Some(range_subtag), Some(language_subtag)) => {
+                                    !range_subtag.eq_ignore_ascii_case(language_subtag)
+                                }
+                                (Some(_), None) => true,
+                                (None, _) => false,
+                            },
+                        )
                     }
                     .into(),
                 )
@@ -1349,3 +1353,27 @@ impl<'a, S: EncodedQuadsStore> Iterator for DescribeIterator<'a, S> {
         }
     }
 }
+
+struct ZipLongest<T1, T2, I1: Iterator<Item = T1>, I2: Iterator<Item = T2>> {
+    a: I1,
+    b: I2,
+}
+
+impl<T1, T2, I1: Iterator<Item = T1>, I2: Iterator<Item = T2>> ZipLongest<T1, T2, I1, I2> {
+    fn new(a: I1, b: I2) -> Self {
+        Self { a, b }
+    }
+}
+
+impl<T1, T2, I1: Iterator<Item = T1>, I2: Iterator<Item = T2>> Iterator
+    for ZipLongest<T1, T2, I1, I2>
+{
+    type Item = (Option<T1>, Option<T2>);
+
+    fn next(&mut self) -> Option<(Option<T1>, Option<T2>)> {
+        match (self.a.next(), self.b.next()) {
+            (None, None) => None,
+            r => Some(r),
+        }
+    }
+}
diff --git a/lib/tests/sparql_test_cases.rs b/lib/tests/sparql_test_cases.rs
index e29d6582..a7a0f2c7 100644
--- a/lib/tests/sparql_test_cases.rs
+++ b/lib/tests/sparql_test_cases.rs
@@ -178,13 +178,6 @@ fn sparql_w3c_query_evaluation_testsuite() {
         NamedNode::from_str(
             "http://www.w3.org/2001/sw/DataAccess/tests/data-r2/expr-builtin/manifest#dawg-lang-3",
         ).unwrap(),
-        //Difference in language matching
-        NamedNode::from_str(
-            "http://www.w3.org/2001/sw/DataAccess/tests/data-r2/expr-builtin/manifest#dawg-langMatches-basic",
-        ).unwrap(),
-        NamedNode::from_str(
-            "http://www.w3.org/2001/sw/DataAccess/tests/data-r2/expr-builtin/manifest#dawg-langMatches-basic",
-        ).unwrap(),
         //DATATYPE("foo"@en) returns rdf:langString in SPARQL 1.1
         NamedNode::from_str(
             "http://www.w3.org/2001/sw/DataAccess/tests/data-r2/expr-builtin/manifest#dawg-datatype-2",