Prefer longest match in path dependency search

src/directory.rs

@@ -2,7 +2,7 @@ use serde::de::{Deserialize, Deserializer};
 use serde_derive::Serialize;
 use std::borrow::Cow;
 use std::env;
-use std::ffi::OsString;
+use std::ffi::{OsStr, OsString};
 use std::io;
 use std::path::{Path, PathBuf};
 
@@ -27,6 +27,10 @@ impl Directory {
         self.path.to_string_lossy()
     }
 
+    pub fn as_os_str(&self) -> &OsStr {
+        self.path.as_os_str()
+    }
+
     pub fn join<P: AsRef<Path>>(&self, tail: P) -> PathBuf {
         self.path.join(tail)
     }

src/run.rs

@@ -11,6 +11,7 @@ use crate::normalize::{self, Context, Normalization, Variations};
 use crate::path::CanonicalPath;
 use crate::{Expected, Runner, Test, features};
 use serde_derive::Deserialize;
+use std::cmp::Reverse;
 use std::collections::{BTreeMap as Map, BTreeSet as Set};
 use std::env;
 use std::ffi::{OsStr, OsString};
@@ -164,6 +165,10 @@ impl Runner {
             );
         }
 
+        // Sort by decreasing path length so that a linear scan can use the
+        // first match knowing it is the longest match.
+        path_dependencies.sort_by_key(|dep| Reverse(dep.normalized_path.as_os_str().len()));
+
         let crate_name = &source_manifest.package.name;
         let project_dir = path!(target_dir / "tests" / "trybuild" / crate_name /);
         fs::create_dir_all(&project_dir)?;