Fix upgrading of pre-release.

Author: torhovland

src/cargo/util/toml_mut/upgrade.rs

@@ -1,7 +1,5 @@
 use std::fmt::Display;
 
-use anyhow::bail;
-
 use crate::CargoResult;
 
 /// Upgrade an existing requirement to a new version.
@@ -23,15 +21,18 @@ pub(crate) fn upgrade_requirement(
             .map(|p| set_comparator(p, version))
             .collect();
         let comparators = comparators?;
-        let new_req = semver::VersionReq { comparators };
+        let mut new_req = semver::VersionReq { comparators };
+        // Validate contract
+        if !new_req.matches(version) {
+            // If req is ^0.1 and version is 0.2.0-beta, new_req becomes ^0.2.
+            // This does not match version. In such cases, we should let new_req
+            // be ^version.
+            new_req = semver::VersionReq::parse(&format!("^{version}"))?;
+        }
         let mut new_req_text = new_req.to_string();
         if new_req_text.starts_with('^') && !req.starts_with('^') {
             new_req_text.remove(0);
         }
-        // Validate contract
-        if !new_req.matches(version) {
-            bail!("new requirement {new_req_text} is invalid, because it doesn't match {version}")
-        }
         if new_req_text == req_text {
             Ok(None)
         } else {

tests/testsuite/update.rs

@@ -1785,7 +1785,7 @@ fn update_precise_breaking_alternative() {
 }
 
 #[cargo_test]
-fn update_precise_breaking_pre_release_cannot_upgrade_nonexplicit_version_req() {
+fn update_precise_breaking_pre_release() {
     Package::new("pre", "0.1.0").publish();
 
     let p = project()
@@ -1811,9 +1811,9 @@ fn update_precise_breaking_pre_release_cannot_upgrade_nonexplicit_version_req()
 
     p.cargo("update -Zunstable-options pre --precise 0.2.0-beta")
         .masquerade_as_nightly_cargo(&["update-precise-breaking"])
-        .with_status(101)
         .with_stderr_data(str![[r#"
-[ERROR] new requirement ^0.2 is invalid, because it doesn't match 0.2.0-beta
+[UPGRADING] pre ^0.1 -> ^0.2.0-beta
+[UPDATING] `dummy-registry` index
 
 "#]])
         .run();