From 54dbc2bf66381314a546b366faa913294af0b6d5 Mon Sep 17 00:00:00 2001
From: Lin Yihai <linyihai@huawei.com>
Date: Wed, 28 Aug 2024 16:04:01 +0800
Subject: [PATCH] fix: Avoid inserting `search_path` again.

---
 src/cargo/core/compiler/compilation.rs | 6 +++++-
 tests/testsuite/build.rs               | 2 +-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/cargo/core/compiler/compilation.rs b/src/cargo/core/compiler/compilation.rs
index 8ec625d77a4..5ecf77d4c6a 100644
--- a/src/cargo/core/compiler/compilation.rs
+++ b/src/cargo/core/compiler/compilation.rs
@@ -323,7 +323,11 @@ impl<'gctx> Compilation<'gctx> {
 
         let dylib_path = paths::dylib_path();
         let dylib_path_is_empty = dylib_path.is_empty();
-        search_path.extend(dylib_path.into_iter());
+        if dylib_path.starts_with(&search_path) {
+            search_path = dylib_path;
+        } else {
+            search_path.extend(dylib_path.into_iter());
+        }
         if cfg!(target_os = "macos") && dylib_path_is_empty {
             // These are the defaults when DYLD_FALLBACK_LIBRARY_PATH isn't
             // set or set to an empty string. Since Cargo is explicitly setting
diff --git a/tests/testsuite/build.rs b/tests/testsuite/build.rs
index 3cc4aa8b8c5..b7c87615437 100644
--- a/tests/testsuite/build.rs
+++ b/tests/testsuite/build.rs
@@ -2178,7 +2178,7 @@ fn issue_14194_deduplicate_library_path_env_var() {
                             let prev_lib_path = std::fs::read_to_string(txt).unwrap();
                             // Ensure no duplicate insertion to dylib search paths
                             // when calling `cargo run` recursively.
-                            assert_ne!(lib_path, prev_lib_path);
+                            assert_eq!(lib_path, prev_lib_path);
                         }}
 
                         if level == 0 {{