Copy .cargo and .xargo correctly

Co-authored-by: josh-bpl <124796608+josh-bpl@users.noreply.github.com>

src/docker/remote.rs

@@ -67,6 +67,16 @@ impl<'a, 'b, 'c> ContainerDataVolume<'a, 'b, 'c> {
         mount_prefix: &str,
         msg_info: &mut MessageInfo,
     ) -> Result<ExitStatus> {
+        if let Some((_, rel)) = reldst.rsplit_once('/') {
+            if src.is_dir() && src.file_name().unwrap().to_utf8()? == rel {
+                eyre::bail!(
+                    "reldst is pointing to the wrong path: {} -> {}\n{}",
+                    src.as_posix_relative()?,
+                    reldst,
+                    std::panic::Location::caller()
+                );
+            }
+        }
         subcommand_or_exit(self.engine, "cp")?
             .arg("-a")
             .arg(src.to_utf8()?)
@@ -196,7 +206,15 @@ impl<'a, 'b, 'c> ContainerDataVolume<'a, 'b, 'c> {
                 mount_prefix,
                 msg_info,
             )?;
-            self.copy_files(dirs.xargo(), &reldst, mount_prefix, msg_info)?;
+            self.copy_files(
+                dirs.xargo(),
+                reldst
+                    .rsplit_once('/')
+                    .ok_or_else(|| eyre::eyre!("cargo can't be a root directory"))?
+                    .0,
+                mount_prefix,
+                msg_info,
+            )?;
         }
 
         Ok(())
@@ -216,7 +234,15 @@ impl<'a, 'b, 'c> ContainerDataVolume<'a, 'b, 'c> {
             .unwrap_or(copy_registry);
 
         if copy_registry {
-            self.copy_files(dirs.cargo(), &reldst, mount_prefix, msg_info)?;
+            self.copy_files(
+                dirs.cargo(),
+                reldst
+                    .rsplit_once('/')
+                    .ok_or_else(|| eyre::eyre!("cargo can't be a root directory"))?
+                    .0,
+                mount_prefix,
+                msg_info,
+            )?;
         } else {
             // can copy a limit subset of files: the rest is present.
             self.create_dir(&reldst, mount_prefix, msg_info)?;