Canonicalize paths only when needed

Author: Jon Gjengset

src/config.rs

@@ -552,11 +552,11 @@ impl Cfg {
                 }
                 OverrideReason::OverrideDB(ref path) => format!(
                     "the directory override for '{}' specifies an uninstalled toolchain",
-                    path.display()
+                    utils::canonicalize_path(path, self.notify_handler.as_ref()).display(),
                 ),
                 OverrideReason::ToolchainFile(ref path) => format!(
                     "the toolchain file at '{}' specifies an uninstalled toolchain",
-                    path.display()
+                    utils::canonicalize_path(path, self.notify_handler.as_ref()).display(),
                 ),
             };
 
@@ -593,8 +593,7 @@ impl Cfg {
         settings: &Settings,
     ) -> Result<Option<(OverrideFile, OverrideReason)>> {
         let notify = self.notify_handler.as_ref();
-        let dir = utils::canonicalize_path(dir, notify);
-        let mut dir = Some(&*dir);
+        let mut dir = Some(dir);
 
         while let Some(d) = dir {
             // First check the override database

src/toolchain.rs

@@ -93,7 +93,7 @@ impl<'a> Toolchain<'a> {
 
         Ok(Toolchain {
             cfg,
-            name: path
+            name: utils::canonicalize_path(&path, cfg.notify_handler.as_ref())
                 .to_str()
                 .ok_or_else(|| ErrorKind::InvalidToolchainPath(path.clone().into()))?
                 .to_owned(),

tests/cli-rustup.rs

@@ -1516,10 +1516,6 @@ fn proxy_override_path() {
 }
 
 #[test]
-#[cfg_attr(
-    windows,
-    ignore = "FIXME: Windows uses UNC paths which do not work with relative paths"
-)]
 fn file_override_path_relative() {
     setup(&|config| {
         expect_ok(config, &["rustup", "default", "stable"]);