fix(linux): a bare node name opens under /dev

`sg3` (or `sr0` with no sg node) was opened relative to the current
directory. It now opens /dev/sg3, as the full path does.

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## [Unreleased]
 
 - Windows: a bare drive letter (`E`) opens that drive, as `E:` does; it was opened as `\\.\E`, which does not exist (E1000).
+- Linux: a bare node name (`sg3`, `sr0`) opens `/dev/sg3` / `/dev/sr0`; it was opened relative to the current directory.
 
 ## [1.8.1] — 2026-10-07
 

src/scsi/linux.rs

@@ -235,6 +235,14 @@ impl SgIoTransport {
     /// Resolve /dev/sr* -> /dev/sg* via sysfs. If already sg, returns as-is.
     /// Falls back to the original path if resolution fails.
     fn resolve_to_sg(device: &Path) -> std::path::PathBuf {
+        // A bare node name (`sr0`, `sg3`) is that node under /dev, as `/dev/sr0` is.
+        let dev_path;
+        let device = if device.parent() == Some(Path::new("")) {
+            dev_path = Path::new("/dev").join(device);
+            dev_path.as_path()
+        } else {
+            device
+        };
         let dev_name = match device.file_name().and_then(|n| n.to_str()) {
             Some(n) => n,
             None => return device.to_path_buf(),

src/scsi/linux_open_error_tests.rs

@@ -10,3 +10,19 @@ fn open_errno_maps_to_its_real_cause() {
     assert!(matches!(map(libc::EMFILE), Error::IoError { .. }));
     assert!(matches!(map(libc::EBUSY), Error::IoError { .. }));
 }
+
+#[test]
+fn a_bare_node_name_opens_under_dev() {
+    assert_eq!(
+        SgIoTransport::resolve_to_sg(Path::new("sg3")),
+        Path::new("/dev/sg3")
+    );
+    assert_eq!(
+        SgIoTransport::resolve_to_sg(Path::new("/dev/sg3")),
+        Path::new("/dev/sg3")
+    );
+    assert_eq!(
+        SgIoTransport::resolve_to_sg(Path::new("./sg3")),
+        Path::new("./sg3")
+    );
+}