fix: update --breaking now handles mixed renaming and pinning.

src/cargo/ops/cargo_update.rs

@@ -363,7 +363,7 @@ fn upgrade_dependency(
         return Ok(dependency);
     }
 
-    let Some(new_req_string) = upgrade_requirement(&current.to_string(), latest)? else {
+    let Some((new_req_string, _)) = upgrade_requirement(&current.to_string(), latest)? else {
         trace!(
             "skipping dependency `{}` because the version requirement didn't change",
             name
@@ -426,41 +426,62 @@ pub fn write_manifest_upgrades(
                     dep_key_str,
                     dep_item,
                 )?;
+                let name = &dependency.name;
+
+                if let Some(renamed_to) = dependency.rename {
+                    trace!(
+                        "skipping dependency renamed from `{}` to `{}`",
+                        name,
+                        renamed_to
+                    );
+                    continue;
+                }
 
                 let Some(current) = dependency.version() else {
-                    trace!("skipping dependency without a version: {}", dependency.name);
+                    trace!("skipping dependency without a version: {}", name);
                     continue;
                 };
 
                 let (MaybeWorkspace::Other(source_id), Some(Source::Registry(source))) =
                     (dependency.source_id(ws.gctx())?, dependency.source())
                 else {
-                    trace!("skipping non-registry dependency: {}", dependency.name);
+                    trace!("skipping non-registry dependency: {}", name);
                     continue;
                 };
 
-                let Some(latest) = upgrades.get(&(dependency.name.to_owned(), source_id)) else {
+                let Some(latest) = upgrades.get(&(name.to_owned(), source_id)) else {
+                    trace!("skipping dependency without an upgrade: {}", name);
+                    continue;
+                };
+
+                let Some((new_req_string, new_req)) = upgrade_requirement(current, latest)? else {
                     trace!(
-                        "skipping dependency without an upgrade: {}",
-                        dependency.name
+                        "skipping dependency `{}` because the version requirement didn't change",
+                        name
                     );
                     continue;
                 };
 
-                let Some(new_req_string) = upgrade_requirement(current, latest)? else {
+                let [comparator] = &new_req.comparators[..] else {
                     trace!(
-                        "skipping dependency `{}` because the version requirement didn't change",
-                        dependency.name
+                        "skipping dependency `{}` with multiple version comparators: {:?}",
+                        name,
+                        new_req.comparators
                     );
                     continue;
                 };
 
+                if comparator.op != Op::Caret {
+                    trace!("skipping non-caret dependency `{}`: {}", name, comparator);
+                    continue;
+                }
+
                 let mut dep = dependency.clone();
                 let mut source = source.clone();
                 source.version = new_req_string;
                 dep.source = Some(Source::Registry(source));
 
-                trace!("upgrading dependency {}", dependency.name);
+                trace!("upgrading dependency {}", name);
                 dep.update_toml(&crate_root, &mut dep_key, dep_item);
                 manifest_has_changed = true;
                 any_file_has_changed = true;

src/cargo/util/toml_mut/upgrade.rs

@@ -7,7 +7,7 @@ use crate::CargoResult;
 pub(crate) fn upgrade_requirement(
     req: &str,
     version: &semver::Version,
-) -> CargoResult<Option<String>> {
+) -> CargoResult<Option<(String, semver::VersionReq)>> {
     let req_text = req.to_string();
     let raw_req = semver::VersionReq::parse(&req_text)
         .expect("semver to generate valid version requirements");
@@ -40,7 +40,7 @@ pub(crate) fn upgrade_requirement(
         if new_req_text == req_text {
             Ok(None)
         } else {
-            Ok(Some(new_req_text))
+            Ok(Some((new_req_text, new_req)))
         }
     }
 }
@@ -103,9 +103,10 @@ mod test {
         #[track_caller]
         fn assert_req_bump<'a, O: Into<Option<&'a str>>>(version: &str, req: &str, expected: O) {
             let version = semver::Version::parse(version).unwrap();
-            let actual = upgrade_requirement(req, &version).unwrap();
+            let (actual, _) = upgrade_requirement(req, &version).unwrap().unwrap();
+            let actual = actual.as_str();
             let expected = expected.into();
-            assert_eq!(actual.as_deref(), expected);
+            assert_eq!(Some(actual), expected);
         }
 
         #[test]

tests/testsuite/update.rs

@@ -2545,20 +2545,18 @@ fn update_breaking_mixed_pinning_renaming() {
 
     assert_e2e().eq(
         &root_manifest,
-        // FIXME: The pinned dependency should not be upgraded.
         str![[r#"
 
                 [workspace]
                 members = ["foo", "bar"]
 
                 [workspace.dependencies]
-                mixed-ws-pinned = "=2.0"
+                mixed-ws-pinned = "=1.0"
             "#]],
     );
 
     assert_e2e().eq(
         &foo_manifest,
-        // FIXME: The pinned and renamed dependencies should not be upgraded.
         str![[r#"
 
                 [package]
@@ -2568,9 +2566,9 @@ fn update_breaking_mixed_pinning_renaming() {
                 authors = []
 
                 [dependencies]
-                mixed-pinned = "=2.0"
+                mixed-pinned = "=1.0"
                 mixed-ws-pinned.workspace = true
-                renamed-to = { package = "renamed-from", version = "2.0" }
+                renamed-to = { package = "renamed-from", version = "1.0" }
             "#]],
     );