Factor out workspace reloading

This factors out the code to reload a workspace since I will be needing
to reuse this elsewhere.

There is some risk with this method not getting updated correctly in the
future as new fields are added to Workspace (and it may be missing some
things now), but that is an issue with the existing code.

Author: ehuss

src/bin/cargo/commands/fix.rs

@@ -94,7 +94,6 @@ pub fn exec(gctx: &mut GlobalContext, args: &ArgMatches) -> CliResult {
     ops::fix(
         gctx,
         &ws,
-        &root_manifest,
         &mut ops::FixOptions {
             edition: args.flag("edition"),
             idioms: args.flag("edition-idioms"),

src/cargo/core/workspace.rs

@@ -301,6 +301,18 @@ impl<'gctx> Workspace<'gctx> {
         Ok(ws)
     }
 
+    /// Reloads the workspace.
+    ///
+    /// This is useful if the workspace has been updated, such as with `cargo
+    /// fix` modifying the `Cargo.toml` file.
+    pub fn reload(&self, gctx: &'gctx GlobalContext) -> CargoResult<Workspace<'gctx>> {
+        let mut ws = Workspace::new(self.root_manifest(), gctx)?;
+        ws.set_resolve_honors_rust_version(Some(self.resolve_honors_rust_version));
+        ws.set_resolve_feature_unification(self.resolve_feature_unification);
+        ws.set_requested_lockfile_path(self.requested_lockfile_path.clone());
+        Ok(ws)
+    }
+
     fn set_resolve_behavior(&mut self) -> CargoResult<()> {
         // - If resolver is specified in the workspace definition, use that.
         // - If the root package specifies the resolver, use that.

src/cargo/ops/fix.rs

@@ -103,7 +103,6 @@ pub struct FixOptions {
 pub fn fix(
     gctx: &GlobalContext,
     original_ws: &Workspace<'_>,
-    root_manifest: &Path,
     opts: &mut FixOptions,
 ) -> CargoResult<()> {
     check_version_control(gctx, opts)?;
@@ -120,10 +119,7 @@ pub fn fix(
 
         check_resolver_change(&original_ws, &mut target_data, opts)?;
     }
-    let mut ws = Workspace::new(&root_manifest, gctx)?;
-    ws.set_resolve_honors_rust_version(Some(original_ws.resolve_honors_rust_version()));
-    ws.set_resolve_feature_unification(original_ws.resolve_feature_unification());
-    ws.set_requested_lockfile_path(opts.requested_lockfile_path.clone());
+    let ws = original_ws.reload(gctx)?;
 
     // Spin up our lock server, which our subprocesses will use to synchronize fixes.
     let lock_server = LockServer::new()?;