fix: Skip update --breaking in prerelase version

src/cargo/util/toml_mut/upgrade.rs

@@ -18,9 +18,18 @@ pub(crate) fn upgrade_requirement(
         let comparators: CargoResult<Vec<_>> = raw_req
             .comparators
             .into_iter()
-            .map(|p| set_comparator(p, version))
+            .filter_map(|p| {
+                if p.pre.is_empty() {
+                    Some(set_comparator(p, version))
+                } else {
+                    None
+                }
+            })
             .collect();
-        let comparators = comparators?;
+        let comparators: Vec<_> = comparators?;
+        if comparators.is_empty() {
+            return Ok(None);
+        }
         let new_req = semver::VersionReq { comparators };
         let mut new_req_text = new_req.to_string();
         if new_req_text.starts_with('^') && !req.starts_with('^') {
@@ -217,5 +226,14 @@ mod test {
             assert_req_bump("1.1.1", "=1.0.0", "=1.1.1");
             assert_req_bump("2.0.0", "=1.0.0", "=2.0.0");
         }
+
+        #[test]
+        fn ignore_prerelease() {
+            assert_req_bump("1.7.0", "2.0.0-beta.21", None);
+            assert_req_bump("1.7.0", ">=2.0.0-beta.21", None);
+            assert_req_bump("1.7.0", ">2.0.0-beta.21", None);
+            assert_req_bump("1.7.0", "<=2.0.0-beta.21", None);
+            assert_req_bump("1.7.0", "<2.0.0-beta.21", None);
+        }
     }
 }

tests/testsuite/update.rs

@@ -2616,3 +2616,37 @@ fn update_breaking_mixed_pinning_renaming() {
             "#]],
     );
 }
+
+#[cargo_test]
+fn update_breaking_pre_release() {
+    Package::new("bar", "2.0.0-beta.21").publish();
+
+    let p = project()
+        .file(
+            "Cargo.toml",
+            r#"
+        [package]
+        name  =  "foo"
+        version  =  "0.0.1"
+        edition  =  "2015"
+        authors  =  []
+
+        [dependencies]
+        bar = "2.0.0-beta.21"
+    "#,
+        )
+        .file("src/lib.rs", "")
+        .build();
+
+    p.cargo("generate-lockfile").run();
+
+    Package::new("bar", "1.7.0").publish();
+
+    p.cargo("update -Zunstable-options --breaking bar")
+        .masquerade_as_nightly_cargo(&["update-breaking"])
+        .with_stderr_data(str![[r#"
+[UPDATING] `dummy-registry` index
+
+"#]])
+        .run();
+}