Auto merge of #7855 - ehuss:fix-required-features-renamed, r=alexcrichton

Fix required-features using renamed dependencies.

The dep_name/feat_name syntax in required-features should use the "name in toml" for dep_name, not the actual package name.  Otherwise, it is impossible to actually enable the feature (because the `--features` flag expects a "name in toml").

src/cargo/ops/cargo_compile.rs

@@ -903,9 +903,11 @@ fn resolve_all_features(
 
     // Include features enabled for use by dependencies so targets can also use them with the
     // required-features field when deciding whether to be built or skipped.
-    for (dep, _) in resolve_with_overrides.deps(package_id) {
+    for (dep_id, deps) in resolve_with_overrides.deps(package_id) {
-        for feature in resolve_with_overrides.features(dep) {
+        for feature in resolve_with_overrides.features(dep_id) {
-            features.insert(dep.name().to_string() + "/" + feature);
+            for dep in deps {
+                features.insert(dep.name_in_toml().to_string() + "/" + feature);
+            }
         }
     }
 

tests/testsuite/required_features.rs

@@ -1163,3 +1163,96 @@ available binaries: foo1, foo2",
         )
         .run();
 }
+
+#[cargo_test]
+fn renamed_required_features() {
+    // Test that required-features uses renamed package feature names.
+    let p = project()
+        .file(
+            "Cargo.toml",
+            r#"
+            [package]
+            name = "foo"
+            version = "0.1.0"
+            edition = "2018"
+
+            [[bin]]
+            name = "x"
+            required-features = ["a1/f1"]
+
+            [dependencies]
+            a1 = {path="a1", package="a"}
+            a2 = {path="a2", package="a"}
+            "#,
+        )
+        .file(
+            "src/bin/x.rs",
+            r#"
+            fn main() {
+                a1::f();
+                a2::f();
+            }
+            "#,
+        )
+        .file(
+            "a1/Cargo.toml",
+            r#"
+            [package]
+            name = "a"
+            version = "0.1.0"
+
+            [features]
+            f1 = []
+            "#,
+        )
+        .file(
+            "a1/src/lib.rs",
+            r#"
+            pub fn f() {
+                if cfg!(feature="f1") {
+                    println!("a1 f1");
+                }
+            }
+            "#,
+        )
+        .file(
+            "a2/Cargo.toml",
+            r#"
+             [package]
+            name = "a"
+            version = "0.2.0"
+
+            [features]
+            f2 = []
+           "#,
+        )
+        .file(
+            "a2/src/lib.rs",
+            r#"
+            pub fn f() {
+                if cfg!(feature="f2") {
+                    println!("a2 f2");
+                }
+            }
+            "#,
+        )
+        .build();
+
+    p.cargo("run")
+        .with_status(101)
+        .with_stderr(
+            "\
+[ERROR] target `x` in package `foo` requires the features: `a1/f1`
+Consider enabling them by passing, e.g., `--features=\"a1/f1\"`
+",
+        )
+        .run();
+
+    p.cargo("build --features a1/f1").run();
+    p.rename_run("x", "x_with_f1").with_stdout("a1 f1").run();
+
+    p.cargo("build --features a1/f1,a2/f2").run();
+    p.rename_run("x", "x_with_f1_f2")
+        .with_stdout("a1 f1\na2 f2")
+        .run();
+}