Auto merge of #3818 - jmatraszek:3814-run_proper_binary_main_rs, r=al…

…excrichton

Fixes #3814

src/cargo/util/toml.rs

@@ -1270,7 +1270,12 @@ fn normalize(package_root: &Path,
                 if package_root.join(&default_bin_path.0).exists() {
                     default_bin_path // inferred from bin's name
                 } else {
-                    PathValue(Path::new("src").join("main.rs"))
+                    let path = PathValue(Path::new("src").join("main.rs"));
+                    if package_root.join(&path.0).exists() {
+                        path
+                    } else {
+                        PathValue(Path::new("src").join("bin").join("main.rs"))
+                    }
                 }
             });
             let mut target = Target::bin_target(&bin.name(), package_root.join(&path.0),

tests/build.rs

@@ -2849,3 +2849,24 @@ fn run_proper_binary() {
     assert_that(p.cargo_process("run").arg("--bin").arg("other"),
                 execs().with_status(0));
 }
+
+#[test]
+fn run_proper_binary_main_rs() {
+    let p = project("foo")
+        .file("Cargo.toml", r#"
+            [package]
+            name = "foo"
+            authors = []
+            version = "0.0.0"
+            [[bin]]
+            name = "foo"
+        "#)
+        .file("src/lib.rs", "")
+        .file("src/bin/main.rs", r#"
+            fn main() {
+            }
+        "#);
+
+    assert_that(p.cargo_process("run").arg("--bin").arg("foo"),
+                execs().with_status(0));
+}