Auto merge of #12975 - epage:git, r=weihanglo

fix(resolver): Don't do git fetches when updating workspace members

### What does this PR try to resolve?

Before, when running `cargo update <member>`, we'd not reuse the
previous resolve result and when the resolver started walking into the
dependencies, it would do a git fetch.

Now, we won't even try to resolve the workspace members and so we won't
look at those dependencies and do git fetch.

This will make `cargo update <workspace-member>`
match `cargo update --workspace`.

Fixes #12599
Fixes #8821

### How should we test and review this PR?

I considered whether there were other ways of handling this but I
figured aiming for consistency in approaches was the best way.
We can investigate improving those approaches separately.

There are other discrepancies in the different code paths (handling of
patches, adding sources) but I'm deferring looking over those.

I added a test to demonstrate the `--workspace` behavior to use as a base line to compare with.

### Additional information

Between this and #12602, this should finally resolve #12599.

Author: bors

src/cargo/ops/cargo_generate_lockfile.rs

@@ -122,6 +122,26 @@ pub fn update_lockfile(ws: &Workspace<'_>, opts: &UpdateOptions<'_>) -> CargoRes
             }
         }
 
+        // Mirror `--workspace` and never avoid workspace members.
+        // Filtering them out here so the above processes them normally
+        // so their dependencies can be updated as requested
+        to_avoid = to_avoid
+            .into_iter()
+            .filter(|id| {
+                for package in ws.members() {
+                    let member_id = package.package_id();
+                    // Skip checking the `version` because `previous_resolve` might have a stale
+                    // value.
+                    // When dealing with workspace members, the other fields should be a
+                    // sufficiently unique match.
+                    if id.name() == member_id.name() && id.source_id() == member_id.source_id() {
+                        return false;
+                    }
+                }
+                true
+            })
+            .collect();
+
         registry.add_sources(sources)?;
     }
 

tests/testsuite/update.rs

@@ -1091,11 +1091,8 @@ rustdns.workspace = true
     p.cargo("update -p rootcrate")
         .with_stderr(&format!(
             "\
-[UPDATING] git repository `{}`
 [UPDATING] rootcrate v2.29.8 ([CWD]/rootcrate) -> v2.29.81
-[UPDATING] rustdns v0.5.0 ([..]) -> [..]
 [UPDATING] subcrate v2.29.8 ([CWD]/subcrate) -> v2.29.81",
-            git_project.url(),
         ))
         .run();
 }
@@ -1182,11 +1179,96 @@ rustdns.workspace = true
     p.cargo("update -p crate2")
         .with_stderr(&format!(
             "\
-[UPDATING] git repository `{}`
 [UPDATING] crate1 v2.29.8 ([CWD]/crate1) -> v2.29.81
-[UPDATING] crate2 v2.29.8 ([CWD]/crate2) -> v2.29.81
-[UPDATING] rustdns v0.5.0 ([..]) -> [..]",
+[UPDATING] crate2 v2.29.8 ([CWD]/crate2) -> v2.29.81",
+        ))
+        .run();
+}
+
+#[cargo_test]
+fn update_only_members_with_workspace() {
+    let git_project = git::new("rustdns", |project| {
+        project
+            .file("Cargo.toml", &basic_lib_manifest("rustdns"))
+            .file("src/lib.rs", "pub fn bar() {}")
+    });
+
+    let workspace_toml = format!(
+        r#"
+[workspace.package]
+version = "2.29.8"
+edition = "2021"
+publish = false
+
+[workspace]
+members = [
+    "crate2",
+    "crate1",
+]
+resolver = "2"
+
+[workspace.dependencies]
+# Internal crates
+crate1 = {{ version = "*", path = "./crate1" }}
+
+# External dependencies
+rustdns = {{ version = "0.5.0", default-features = false, git = "{}" }}
+                "#,
+        git_project.url()
+    );
+    let p = project()
+        .file("Cargo.toml", &workspace_toml)
+        .file(
+            "crate2/Cargo.toml",
+            r#"
+[package]
+name = "crate2"
+version.workspace = true
+edition.workspace = true
+publish.workspace = true
+
+[dependencies]
+crate1.workspace = true
+"#,
+        )
+        .file("crate2/src/main.rs", "fn main() {}")
+        .file(
+            "crate1/Cargo.toml",
+            r#"
+[package]
+name = "crate1"
+version.workspace = true
+edition.workspace = true
+publish.workspace = true
+
+[dependencies]
+rustdns.workspace = true
+"#,
+        )
+        .file("crate1/src/lib.rs", "pub foo() {}")
+        .build();
+
+    // First time around we should compile both foo and bar
+    p.cargo("generate-lockfile")
+        .with_stderr(&format!(
+            "[UPDATING] git repository `{}`\n",
             git_project.url(),
         ))
         .run();
+    // Modify a file manually, shouldn't trigger a recompile
+    git_project.change_file("src/lib.rs", r#"pub fn bar() { println!("hello!"); }"#);
+    // Commit the changes and make sure we don't trigger a recompile because the
+    // lock file says not to change
+    let repo = git2::Repository::open(&git_project.root()).unwrap();
+    git::add(&repo);
+    git::commit(&repo);
+    p.change_file("Cargo.toml", &workspace_toml.replace("2.29.8", "2.29.81"));
+
+    p.cargo("update --workspace")
+        .with_stderr(
+            "\
+[UPDATING] crate1 v2.29.8 ([CWD]/crate1) -> v2.29.81
+[UPDATING] crate2 v2.29.8 ([CWD]/crate2) -> v2.29.81",
+        )
+        .run();
 }