Tests: check that config.toml warning is suppressed with reverse link

Author: ijackson

tests/testsuite/config.rs

@@ -326,6 +326,22 @@ fn config_ambiguous_filename_symlink_doesnt_warn_relative() {
     });
 }
 
+#[cfg(unix)]
+#[cargo_test]
+fn config_ambiguous_filename_symlink_doesnt_warn_backwards() {
+    config_ambiguous_filename_symlink_doesnt_warn_general(|| {
+        let root = paths::root();
+        t!(fs::rename(
+            root.join(".cargo/config.toml"),
+            root.join(".cargo/config")
+        ));
+        t!(symlink_file(
+            Path::new("config"),
+            &root.join(".cargo/config.toml")
+        ));
+    });
+}
+
 #[cargo_test]
 fn config_ambiguous_filename() {
     write_config_extless(