feat: support xml+svg and svg

src/map.rs

@@ -227,6 +227,12 @@ matcher_map!(
         "dwg",
         matchers::image::is_dwg
     ),
+    (
+        MatcherType::Image,
+        "image/svg+xml",
+        "svg",
+        matchers::image::is_svg
+    ),
     // Video
     (
         MatcherType::Video,

src/matchers/image.rs

@@ -227,6 +227,25 @@ pub fn is_djvu(buf: &[u8]) -> bool {
         && buf[14] == 0x56
 }
 
+/// Returns whether a buffer is SVG image data.
+#[must_use]
+pub fn is_svg(buf: &[u8]) -> bool {
+    if buf.starts_with(b"<svg") {
+        return true;
+    }
+
+    // Avoid conflicts with other XML types while detecting SVGs.
+    if buf.starts_with(b"<?xml") {
+        return buf
+            .get(..256)
+            .unwrap_or(buf)
+            .windows(4)
+            .any(|w| w == b"<svg");
+    }
+
+    false
+}
+
 /// Returns whether a buffer is an AutoCAD Drawing (DWG).
 #[must_use]
 pub fn is_dwg(buf: &[u8]) -> bool {

src/matchers/text.rs

@@ -47,7 +47,7 @@ pub fn is_xml(buf: &[u8]) -> bool {
     let val: &[u8] = b"<?xml";
     let buf = trim_start_whitespaces(buf);
     let buf = trim_start_byte_order_marks(buf);
-    starts_with_ignore_ascii_case(buf, val)
+    starts_with_ignore_ascii_case(buf, val) && !super::image::is_svg(buf) // try avoid detecting XML-declared SVGs
 }
 
 /// Strip whitespaces at the beginning of the buffer.
@@ -88,7 +88,7 @@ pub fn is_shellscript(buf: &[u8]) -> bool {
 
 #[cfg(test)]
 mod tests {
-    use super::{is_html, is_shellscript, trim_start_whitespaces};
+    use super::{is_html, is_shellscript, is_xml, trim_start_whitespaces};
 
     #[test]
     fn trim_whitespaces() {
@@ -114,4 +114,12 @@ mod tests {
     fn shellscript() {
         assert!(!is_shellscript(b"#!"));
     }
+
+    #[test]
+    fn xml_excludes_svg() {
+        assert!(!is_xml(
+            b"<?xml version=\"1.0\"?>\n<svg xmlns=\"http://www.w3.org/2000/svg\">"
+        ));
+        assert!(is_xml(b"<?xml version=\"1.0\"?>\n<note/>"));
+    }
 }

tests/image.rs

@@ -37,3 +37,7 @@ test_format!(Image, "image/vnd.djvu", "djvu", djvu1, "sample_single.djvu");
 test_format!(Image, "image/vnd.djvu", "djvu", djvu2, "sample_multi.djvu");
 
 test_format!(Image, "image/vnd.dwg", "dwg", dwg, "sample.dwg");
+
+test_format!(Image, "image/svg+xml", "svg", svg, "sample.svg");
+
+test_format!(Image, "image/svg+xml", "svg", svg2, "sample2.svg");