Fix for "Running cargo update without a Cargo.lock ignores arguments" #6872

src/cargo/ops/cargo_generate_lockfile.rs

@@ -46,7 +46,19 @@ pub fn update_lockfile(ws: &Workspace<'_>, opts: &UpdateOptions<'_>) -> CargoRes
 
     let previous_resolve = match ops::load_pkg_lockfile(ws)? {
         Some(resolve) => resolve,
-        None => return generate_lockfile(ws),
+        None => {
+            match opts.precise {
+                None => return generate_lockfile(ws),
+
+                // Precise option specified, so calculate a previous_resolve required
+                // by precise package update later.
+                Some(_) => {
+                    let mut registry = PackageRegistry::new(opts.config)?;
+                    ops::resolve_with_previous(&mut registry, ws, Method::Everything,
+                                               None, None, &[], true)?
+                }
+            }
+        }
     };
     let mut registry = PackageRegistry::new(opts.config)?;
     let mut to_avoid = HashSet::new();

tests/testsuite/update.rs

@@ -395,6 +395,168 @@ fn update_precise() {
         .run();
 }
 
+// cargo update should respect its arguments even without a lockfile.
+// See issue "Running cargo update without a Cargo.lock ignores arguments"
+// at <https://github.com/rust-lang/cargo/issues/6872>.
+#[test]
+fn update_precise_first_run() {
+    Package::new("serde", "0.1.0").publish();
+    Package::new("serde", "0.2.0").publish();
+    Package::new("serde", "0.2.1").publish();
+
+    let p = project()
+        .file(
+            "Cargo.toml",
+            r#"
+                [package]
+                name = "bar"
+                version = "0.0.1"
+
+                [dependencies]
+                serde = "0.2"
+            "#,
+        )
+        .file("src/lib.rs", "")
+        .build();
+
+    p.cargo("update -p serde --precise 0.2.0")
+        .with_stderr(
+            "\
+[UPDATING] `[..]` index
+[UPDATING] serde v0.2.1 -> v0.2.0
+",
+        )
+        .run();
+
+    // Assert `cargo metadata` shows serde 0.2.0
+    p.cargo("metadata")
+        .with_json(
+            r#"{
+  "packages": [
+    {
+      "authors": [],
+      "categories": [],
+      "dependencies": [],
+      "description": null,
+      "edition": "2015",
+      "features": {},
+      "id": "serde 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+      "keywords": [],
+      "license": null,
+      "license_file": null,
+      "links": null,
+      "manifest_path": "[..]/home/.cargo/registry/src/-[..]/serde-0.2.0/Cargo.toml",
+      "metadata": null,
+      "name": "serde",
+      "readme": null,
+      "repository": null,
+      "source": "registry+https://github.com/rust-lang/crates.io-index",
+      "targets": [
+        {
+          "crate_types": [
+            "lib"
+          ],
+          "edition": "2015",
+          "kind": [
+            "lib"
+          ],
+          "name": "serde",
+          "src_path": "[..]/home/.cargo/registry/src/-[..]/serde-0.2.0/src/lib.rs"
+        }
+      ],
+      "version": "0.2.0"
+    },
+    {
+      "authors": [],
+      "categories": [],
+      "dependencies": [
+        {
+          "features": [],
+          "kind": null,
+          "name": "serde",
+          "optional": false,
+          "registry": null,
+          "rename": null,
+          "req": "^0.2",
+          "source": "registry+https://github.com/rust-lang/crates.io-index",
+          "target": null,
+          "uses_default_features": true
+        }
+      ],
+      "description": null,
+      "edition": "2015",
+      "features": {},
+      "id": "bar 0.0.1 (path+file://[..]/foo)",
+      "keywords": [],
+      "license": null,
+      "license_file": null,
+      "links": null,
+      "manifest_path": "[..]/foo/Cargo.toml",
+      "metadata": null,
+      "name": "bar",
+      "readme": null,
+      "repository": null,
+      "source": null,
+      "targets": [
+        {
+          "crate_types": [
+            "lib"
+          ],
+          "edition": "2015",
+          "kind": [
+            "lib"
+          ],
+          "name": "bar",
+          "src_path": "[..]/foo/src/lib.rs"
+        }
+      ],
+      "version": "0.0.1"
+    }
+  ],
+  "resolve": {
+    "nodes": [
+      {
+        "dependencies": [
+          "serde 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)"
+        ],
+        "deps": [
+          {
+            "name": "serde",
+            "pkg": "serde 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)"
+          }
+        ],
+        "features": [],
+        "id": "bar 0.0.1 (path+file://[..]/foo)"
+      },
+      {
+        "dependencies": [],
+        "deps": [],
+        "features": [],
+        "id": "serde 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)"
+      }
+    ],
+    "root": "bar 0.0.1 (path+file://[..]/foo)"
+  },
+  "target_directory": "[..]/foo/target",
+  "version": 1,
+  "workspace_members": [
+    "bar 0.0.1 (path+file://[..]/foo)"
+  ],
+  "workspace_root": "[..]/foo"
+}"#,
+        )
+        .run();
+
+    p.cargo("update -p serde --precise 0.2.0")
+        .with_stderr(
+            "\
+[UPDATING] `[..]` index
+",
+        )
+        .run();
+
+}
+
 #[test]
 fn preserve_top_comment() {
     let p = project().file("src/lib.rs", "").build();