test(update): show cross-registry multi-spec precise

tests/testsuite/update.rs

@@ -1713,6 +1713,139 @@ checksum = "abac7d6286c36aa99d7f6691c6802e3d77249866cc4966c8eb49a03945996cf6"
     );
 }
 
+/// This pins down today's behavior when multiple specs live on different registries
+/// Unsure if it is intended or an overlook or a bug.
+#[cargo_test]
+fn precise_with_multiple_specs_cross_registry() {
+    registry::alt_init();
+    Package::new("reg", "1.0.0").publish();
+    Package::new("reg", "1.0.1").publish();
+    Package::new("alt", "1.0.0").alternative(true).publish();
+    Package::new("alt", "1.0.1").alternative(true).publish();
+    Package::new("reg2", "1.1.0").publish();
+    Package::new("reg2", "1.2.0").publish();
+    Package::new("alt2", "1.1.0").alternative(true).publish();
+    Package::new("alt2", "1.2.0").alternative(true).publish();
+
+    let p = project()
+        .file(
+            "Cargo.toml",
+            r#"
+                [package]
+                name = "foo"
+                edition = "2021"
+
+                [dependencies]
+                reg = "1"
+                alt = { version = "1", registry = "alternative" }
+                reg2 = "1"
+                alt2 = { version = "1", registry = "alternative" }
+            "#,
+        )
+        .file("src/lib.rs", "")
+        .build();
+    p.cargo("generate-lockfile").run();
+
+    assert_e2e().eq(
+        p.read_lockfile(),
+        str![[r##"
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "alt"
+version = "1.0.1"
+source = "registry+[ROOTURL]/alternative-registry"
+checksum = "4e902d03b37e49f6758c6f2b7d57c96e458774ba6c2607d480892ebe48b0a293"
+
+[[package]]
+name = "alt2"
+version = "1.2.0"
+source = "registry+[ROOTURL]/alternative-registry"
+checksum = "63dab2653af81cc9dd6c4308ed1808f13a219fa3043d8a16f36b4605f8df1293"
+
+[[package]]
+name = "foo"
+version = "0.0.0"
+dependencies = [
+ "alt",
+ "alt2",
+ "reg",
+ "reg2",
+]
+
+[[package]]
+name = "reg"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f2422bba45503c8f60ce4a35b8bb8ed55e8517e5c455883f7128b3363b3ba270"
+
+[[package]]
+name = "reg2"
+version = "1.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9c18cfe95beecfbe2d462deee1a87483f99d0254edbe80d247178953337ef075"
+
+"##]],
+    );
+
+    // Current behavior `--precise` update only what it matches and ignore others.
+    p.cargo("update -p reg -p alt -p reg2 -p alt2 --precise 1.0.0")
+        .with_stderr_data(str![[r#"
+[UPDATING] `alternative` index
+[UPDATING] `dummy-registry` index
+[DOWNGRADING] alt v1.0.1 (registry `alternative`) -> v1.0.0
+[DOWNGRADING] reg v1.0.1 -> v1.0.0
+
+"#]])
+        .run();
+
+    assert_e2e().eq(
+        p.read_lockfile(),
+        str![[r##"
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "alt"
+version = "1.0.0"
+source = "registry+[ROOTURL]/alternative-registry"
+checksum = "e93591c223908cfbc49f6026b0b75a6b02d3a0dbd4eb13e48d8f93276373fdea"
+
+[[package]]
+name = "alt2"
+version = "1.2.0"
+source = "registry+[ROOTURL]/alternative-registry"
+checksum = "63dab2653af81cc9dd6c4308ed1808f13a219fa3043d8a16f36b4605f8df1293"
+
+[[package]]
+name = "foo"
+version = "0.0.0"
+dependencies = [
+ "alt",
+ "alt2",
+ "reg",
+ "reg2",
+]
+
+[[package]]
+name = "reg"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c42cf712c9c99776d156b5bedefb8fe76378b89ca550ab4744e7d71e013095f0"
+
+[[package]]
+name = "reg2"
+version = "1.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9c18cfe95beecfbe2d462deee1a87483f99d0254edbe80d247178953337ef075"
+
+"##]],
+    );
+}
+
 /// This pins down today's behavior.
 /// Unsure if it is intended or an overlook or a bug.
 ///