Add a workaround for netvl/xml-rs#155

Fixes #45

src/dzi/dzi_file.rs

@@ -61,20 +61,4 @@ fn test_dzi() {
     assert_eq!(dzi.get_size().unwrap(), Vec2d { x: 5393, y: 3852 });
     assert_eq!(dzi.get_tile_size(), Vec2d { x: 256, y: 256 });
     assert_eq!(dzi.max_level(), 13);
-}
-
-#[test]
-#[ignore]
-fn test_dzi_with_leading_space() {
-    // See https://github.com/lovasoa/dezoomify-rs/issues/45
-    // Trying to parse a file with a byte order mark
-    let dzi: DziFile = serde_xml_rs::from_str(
-        r#" <?xml version="1.0" encoding="utf-8"?>
-        <Image TileSize="256" Overlap="0" Format="jpg" xmlns="http://schemas.microsoft.com/deepzoom/2008">
-        <Size Width="6261" Height="6047" />
-        </Image>"#,
-    ).unwrap();
-    assert_eq!(dzi.get_size().unwrap(), Vec2d { x: 6261, y: 6047 });
-    assert_eq!(dzi.get_tile_size(), Vec2d { x: 256, y: 256 });
-    assert_eq!(dzi.max_level(), 13);
-}
+}

src/dzi/mod.rs

@@ -36,8 +36,17 @@ impl From<DziError> for DezoomerError {
     }
 }
 
+const BOM: &'static [u8] = &[0xEF, 0xBB, 0xBF]; // UTF8 byte order mark
+
 fn load_from_properties(url: &str, contents: &[u8]) -> Result<ZoomLevels, DziError> {
-    let image_properties: DziFile = serde_xml_rs::from_reader(contents)?;
+
+    // Workaround for https://github.com/netvl/xml-rs/issues/155
+    // which the original author seems unwilling to fix
+    let image_properties: DziFile = serde_xml_rs::from_reader(
+        if contents.starts_with(BOM) {
+            &contents[BOM.len()..]
+        } else { contents }
+    )?;
 
     if image_properties.tile_size == 0 {
         return Err(DziError::InvalidTileSize);
@@ -139,3 +148,15 @@ fn test_panorama() {
         ]
     );
 }
+
+
+#[test]
+fn test_dzi_with_bom() {
+    // See https://github.com/lovasoa/dezoomify-rs/issues/45
+    // Trying to parse a file with a byte order mark
+    let contents = "\u{feff}<?xml version=\"1.0\" encoding=\"utf-8\"?>
+        <Image TileSize=\"256\" Overlap=\"0\" Format=\"jpg\" xmlns=\"http://schemas.microsoft.com/deepzoom/2008\">
+        <Size Width=\"6261\" Height=\"6047\" />
+        </Image>";
+    load_from_properties("http://test.com/test.xml", contents.as_ref()).unwrap();
+}