Better logic

Author: sigurdm

lib/src/solver/version_solver.dart

@@ -610,10 +610,8 @@ class VersionSolver {
         return range.constraint as Version?;
       }
     }
-    if (_type == SolveType.upgrade) {
-      return null;
-    }
-    return _lockFile.packages[package]?.version;
+    final locked = _getLocked(package);
+    return locked?.version;
   }
 
   /// Logs [message] in the context of the current selected packages.

test/upgrade/hosted/upgrade_away_from_retracted_test.dart

@@ -20,4 +20,43 @@ void main() {
     server.retractPackageVersion('foo', '1.5.0');
     await pubUpgrade(output: contains('< foo 1.0.0'));
   });
+
+  test(
+    'upgrade will not downgrade if current version is not unlocked',
+    () async {
+      final server = await servePackages();
+
+      server.serve('foo', '1.0.0');
+      server.serve('foo', '1.5.0');
+
+      server.serve('bar', '1.0.0');
+      server.serve('bar', '1.5.0');
+
+      await d.appDir(dependencies: {'foo': '^1.0.0', 'bar': '^1.0.0'}).create();
+
+      await pubGet(
+        output: allOf(contains('+ foo 1.5.0'), contains('+ bar 1.5.0')),
+      );
+      server.retractPackageVersion('foo', '1.5.0');
+      server.retractPackageVersion('bar', '1.5.0');
+
+      await pubUpgrade(
+        args: ['foo'], // bar stays locked, we are only upgrading foo.
+        output: allOf(contains('< foo 1.0.0'), isNot(contains('bar'))),
+      );
+    },
+  );
+
+  test('downgrade will upgrade if current version is retracted', () async {
+    final server = await servePackages();
+
+    server.serve('foo', '1.0.0');
+
+    await d.appDir(dependencies: {'foo': '^1.0.0'}).create();
+    await pubGet(output: contains('+ foo 1.0.0'));
+    server.serve('foo', '1.5.0');
+
+    server.retractPackageVersion('foo', '1.0.0');
+    await pubDowngrade(output: contains('> foo 1.5.0'));
+  });
 }