test: reproduce transitive bindep dependency bug

This is a unit test reproducing the bindep transitive dependency bug based upon examples from
- rust-lang#10837
- rust-lang#11463

Signed-off-by: Roman Volosatovs <rvolosatovs@riseup.net>

tests/testsuite/artifact_dep.rs

@@ -2447,3 +2447,228 @@ fn with_assumed_host_target_and_optional_build_dep() {
         )
         .run();
 }
+
+#[cargo_test]
+fn same_target_transitive_dependency_deduplication() {
+    // See:
+    // - https://github.com/rust-lang/cargo/issues/10837
+    // - https://github.com/rust-lang/cargo/issues/11463
+    let target = rustc_host();
+    let p = project()
+        .file(
+            "Cargo.toml",
+            &format!(
+                r#"
+                [package]
+                name = "foo"
+                version = "0.1.0"
+                edition = "2021"
+
+                [dependencies]
+                a = {{ path = "a" }}
+                bar = {{ path = "bar", artifact = "bin", target = "{target}" }}
+            "#
+            ),
+        )
+        .file(
+            "src/main.rs",
+            r#"
+                fn main() {}
+            "#,
+        )
+        .file(
+            "bar/Cargo.toml",
+            r#"
+                [package]
+                name = "bar"
+                version = "0.1.0"
+
+                [dependencies]
+                a = { path = "../a", features = ["feature"] }
+            "#,
+        )
+        .file(
+            "bar/src/main.rs",
+            r#"
+                fn main() {}
+            "#,
+        )
+        .file(
+            "a/Cargo.toml",
+            r#"
+                [package]
+                name = "a"
+                version = "0.1.0"
+                edition = "2021"
+
+                [dependencies]
+                b = { path = "../b" }
+                c = { path = "../c" }
+
+                [features]
+                feature = ["c/feature"]
+            "#,
+        )
+        .file(
+            "a/src/lib.rs",
+            r#"
+                use b::Trait as _;
+
+                pub fn use_b_trait(x: &impl c::Trait) {
+                    x.b();
+                }
+            "#,
+        )
+        .file(
+            "b/Cargo.toml",
+            r#"
+                [package]
+                name = "b"
+                version = "0.1.0"
+
+                [dependencies]
+                c = { path = "../c" }
+            "#,
+        )
+        .file(
+            "b/src/lib.rs",
+            r#"
+                pub trait Trait {
+                    fn b(&self) {}
+                }
+
+                impl<T: c::Trait> Trait for T {}
+            "#,
+        )
+        .file(
+            "c/Cargo.toml",
+            r#"
+                [package]
+                name = "c"
+                version = "0.1.0"
+
+                [features]
+                feature = []
+            "#,
+        )
+        .file(
+            "c/src/lib.rs",
+            r#"
+                pub trait Trait {}
+            "#,
+        )
+        .build();
+    p.cargo("build -Z bindeps")
+        .masquerade_as_nightly_cargo(&["bindeps"])
+        .with_stderr(
+            "\
+[COMPILING] c v0.1.0 ([CWD]/c)
+[COMPILING] b v0.1.0 ([CWD]/b)
+[COMPILING] a v0.1.0 ([CWD]/a)
+[COMPILING] bar v0.1.0 ([CWD]/bar)
+[COMPILING] foo v0.1.0 ([CWD])
+[FINISHED] dev [unoptimized + debuginfo] target(s) in [..]
+",
+        )
+        .run();
+}
+
+#[cargo_test]
+fn same_target_transitive_dependency_deduplication_lib() {
+    // See https://github.com/rust-lang/cargo/issues/10837
+    let target = rustc_host();
+    let p = project()
+        .file(
+            "Cargo.toml",
+            &format!(
+                r#"
+                [package]
+                name = "foo"
+                version = "0.1.0"
+                edition = "2021"
+
+                [dependencies]
+                a = {{ path = "a" }}
+                b = {{ path = "b", features = ["feature"] }}
+                bar = {{ path = "bar", artifact = "bin", lib = true, target = "{target}" }}
+            "#
+            ),
+        )
+        .file("src/lib.rs", "")
+        .file(
+            "bar/Cargo.toml",
+            r#"
+                [package]
+                name = "bar"
+                version = "0.1.0"
+                edition = "2021"
+
+                [dependencies]
+                a = { path = "../a", features = ["b"] }
+                b = { path = "../b" }
+            "#,
+        )
+        .file("bar/src/lib.rs", "")
+        .file(
+            "bar/src/main.rs",
+            r#"
+                use b::Trait;
+
+                fn main() {
+                    a::A.b()
+                }
+            "#,
+        )
+        .file(
+            "a/Cargo.toml",
+            r#"
+                [package]
+                name = "a"
+                version = "0.1.0"
+
+                [dependencies]
+                b = { path = "../b", optional = true }
+            "#,
+        )
+        .file(
+            "a/src/lib.rs",
+            r#"
+                pub struct A;
+
+                #[cfg(feature = "b")]
+                impl b::Trait for A {}
+            "#,
+        )
+        .file(
+            "b/Cargo.toml",
+            r#"
+                [package]
+                name = "b"
+                version = "0.1.0"
+
+                [features]
+                feature = []
+            "#,
+        )
+        .file(
+            "b/src/lib.rs",
+            r#"
+                pub trait Trait {
+                    fn b(&self) {}
+                }
+            "#,
+        )
+        .build();
+    p.cargo("build -Z bindeps")
+        .masquerade_as_nightly_cargo(&["bindeps"])
+        .with_stderr(
+            "\
+[COMPILING] b v0.1.0 ([CWD]/b)
+[COMPILING] a v0.1.0 ([CWD]/a)
+[COMPILING] bar v0.1.0 ([CWD]/bar)
+[COMPILING] foo v0.1.0 ([CWD])
+[FINISHED] dev [unoptimized + debuginfo] target(s) in [..]
+",
+        )
+        .run();
+}