Fix for failing to delete files on Freedesktop systems (eg Linux) (#34)

* Fix for failing to delete files on Linux #30

* Fix clippy warnings

* Fix clippy warnings

CHANGELOG.md

@@ -1,6 +1,11 @@
 
 Dates are specified in YYYY-MM-DD format.
 
+# Unreleased
+
+## Changed
+- Fix failing to delete files on some freedesktop (eg Linux) systems when the home was not mounted at the root.
+
 # v2.0.1 on 2021-05-02
 
 ## Changed

src/freedesktop.rs

@@ -30,25 +30,17 @@ impl PlatformTrashContext {
 }
 impl TrashContext {
     pub(crate) fn delete_all_canonicalized(&self, full_paths: Vec<PathBuf>) -> Result<(), Error> {
-        let root = Path::new("/");
         let home_trash = home_trash()?;
         let mount_points = get_mount_points()?;
+        let home_topdir = home_topdir(&mount_points)?;
+        debug!("The home topdir is {:?}", home_topdir);
         let uid = unsafe { libc::getuid() };
         for path in full_paths {
             debug!("Deleting {:?}", path);
-            let mut topdir = None;
-            for mount_point in mount_points.iter() {
-                if mount_point.mnt_dir == root {
-                    continue;
-                }
-                if path.starts_with(&mount_point.mnt_dir) {
-                    topdir = Some(&mount_point.mnt_dir);
-                    break;
-                }
-            }
-            let topdir = if let Some(t) = topdir { t } else { root };
+            let topdir = get_topdir_for_path(&path, &mount_points);
             debug!("The topdir of this file is {:?}", topdir);
-            if topdir == root {
+            if topdir == home_topdir {
+                debug!("The topdir was identical to the home topdir, so moving to the home trash.");
                 // Note that the following function creates the trash folder
                 // and its required subfolders in case they don't exist.
                 move_to_trash(path, &home_trash, topdir)?;
@@ -470,7 +462,7 @@ where
         }
     } else {
         // Symlink or file
-        file(&src, &dst)?;
+        file(src, dst)?;
     }
     Ok(())
 }
@@ -567,6 +559,43 @@ fn home_trash() -> Result<PathBuf, Error> {
     })
 }
 
+fn home_topdir(mnt_points: &[MountPoint]) -> Result<PathBuf, Error> {
+    if let Some(data_home) = std::env::var_os("XDG_DATA_HOME") {
+        if data_home.len() > 0 {
+            let data_home_path = AsRef::<Path>::as_ref(data_home.as_os_str());
+            return Ok(get_topdir_for_path(data_home_path, mnt_points).to_owned());
+        }
+    }
+    if let Some(home) = std::env::var_os("HOME") {
+        if home.len() > 0 {
+            let home_path = AsRef::<Path>::as_ref(home.as_os_str());
+            return Ok(get_topdir_for_path(home_path, mnt_points).to_owned());
+        }
+    }
+    Err(Error::Unknown {
+        description: "Neither the XDG_DATA_HOME nor the HOME environment variable was found".into(),
+    })
+}
+
+fn get_topdir_for_path<'a>(path: &Path, mnt_points: &'a [MountPoint]) -> &'a Path {
+    let root: &'static Path = Path::new("/");
+    let mut topdir = None;
+    for mount_point in mnt_points.iter() {
+        if mount_point.mnt_dir == root {
+            continue;
+        }
+        if path.starts_with(&mount_point.mnt_dir) {
+            topdir = Some(&mount_point.mnt_dir);
+            break;
+        }
+    }
+    if let Some(t) = topdir {
+        t
+    } else {
+        root
+    }
+}
+
 struct MountPoint {
     mnt_dir: PathBuf,
     _mnt_type: String,
@@ -579,11 +608,11 @@ fn get_mount_points() -> Result<Vec<MountPoint>, Error> {
     let mounts_path = CString::new("/proc/mounts").unwrap();
     let mut file =
         unsafe { libc::fopen(mounts_path.as_c_str().as_ptr(), read_arg.as_c_str().as_ptr()) };
-    if file == std::ptr::null_mut() {
+    if file.is_null() {
         let mtab_path = CString::new("/etc/mtab").unwrap();
         file = unsafe { libc::fopen(mtab_path.as_c_str().as_ptr(), read_arg.as_c_str().as_ptr()) };
     }
-    if file == std::ptr::null_mut() {
+    if file.is_null() {
         return Err(Error::Unknown {
             description: "Neither '/proc/mounts' nor '/etc/mtab' could be opened.".into(),
         });
@@ -592,7 +621,7 @@ fn get_mount_points() -> Result<Vec<MountPoint>, Error> {
     let mut result = Vec::new();
     loop {
         let mntent = unsafe { libc::getmntent(file) };
-        if mntent == std::ptr::null_mut() {
+        if mntent.is_null() {
             break;
         }
         let dir = unsafe { CStr::from_ptr((*mntent).mnt_dir).to_str().unwrap() };